Talk:Exoplanet/Archive 1

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Archive 1 Archive 2

Contents

GQ Lupi b, Van Briesbroek 8B

GQ Lupi b isn't an exoplanet but a brown dwarf. This one would fit better: [1] but I don't know how too include it

The problem for the 'planets' found by direct imaging is that for young substellar objects the mass-luminosity function is not known. There are different kinds of models for young planets, some say this is a planet, some say it is a brown dwarf.

What about Van Briesbroek 8B? Or is that a brown dwarf? Archola 14:11, 24 September 2005 (UTC)

Pulsar planets

Should PSR B1257+12's 3 light major planets [2] be included? - Jeandré, 2003-06-06t20:52z

[3] This op-ed piece in the introduction about pseudo-planets that Wolszczan discovered is very very opinionated. There is currently no definition for planet. So any sub-brown-dwarf accretion large enough to be thought of as a planet, that orbits a star, is a planet. The hooey about pulsar planets not being real planets is chauvinistic crap.

If you use the disk-instability model to make giant planets, according to some opinins, these aren't planets either, as a 'real' planet is formed by core accretion, and disk-instability only forms brown-dwarfs.

[4] The definition of what a planet is, is currently under debate. Apparently the criteria were determined on Sept. 14th and if / when the group develops a consensus on the proposal, it will go to the IAU executive committee for a vote. AZ Central News Article --Jeff 17:51, 28 September 2005 (UTC)

PSR B1257+12 D could be defined as a planet if the 2006 redefinition of planet... it's larger than Ceres. 132.205.93.195 03:26, 18 August 2006 (UTC)

Edits 2003/2004

Intro needs clarification: Are they considered a part of Solar System, if not, how close need they be? Because when I first saw the word, I though it's any planet not in the Solar System, like those from other constellations. --Menchi 23:28 12 Jul 2003 (UTC)

Info clarified on Jul 12, 2003 by Oliver Pereira. --Menchi 19:53, Aug 21, 2003 (UTC)

"several million extrasolar comets have also been detected. " I never heard of those. Detecting comets should be much harder than detecting planets. I am tempted to remove this sentence, unless it's backed by some reference source. At18 19:25, 21 Aug 2003 (UTC)

I did a bit of research, and found that many comets have been indirectly inferred. Of course they haven't directly detected - too faint. I'm changing the sentence wording to reflect this fact. At18 21:21, 21 Aug 2003 (UTC)

I removed the space telescope part of this sentence: "Planets orbiting main sequenece stars were not discovered until the 1990's, when new space telescopes good enough were constructed", and rewrote the surrounding paragraph. -Wikibob | Talk 16:46, 2004 Aug 7 (UTC)

Supporting Images

added picture...if anyone can find a better one, that might be a good idea. I'm sure there are better ones out there somewhere. --ScottyBoy900Q 02:13, 08 Oct 2004 (UTC)

Does anyone know of a map showing what is known of our galactic disk and the position of the discovered extra solar planets on it? It would really help to give readers a feel for how widespread the planets are and the reach of our detection methods. It also would give a sense of 'place' to the galaxy. I beleive that the most remote detection is near the edge of the galactic core. --DannyStevens 12:34, 7 June 2006 (UTC)

A map might be a good thing to have. Unfortunately, there are several problems. First of all, of course, space is three-dimensional and hard to portray on a two-dimensional map. Secondly, it's hard to know just how many stars to show. The ones with planets tend to not be very prominent to the unaided eye, so we'd want at least a few "landmark" stars, but it's not clear which ones or how many. Thirdly, there's a problem with the distance scale. If the map just covered a hundred light-years or so, it would leave out many known planets. If it went out far enough to include all or almost all known planets (thousands of light years) then there would be a lot of nearby planets that the map would show as right on top of each other. I haven't even found a copyrighted map, much less a public-domain one, that successfully avoids all those problems. But I'll keep my eyes out. Kevin Nelson 04:53, 26 June 2006 (UTC)
There is no map available, only the types of stars planets are most comonly found. Heavier "metals" are required to form rocky planetesimals and population I stars are canditates and these are found within the disk of a galaxy. Hot O and B type stars do not live long enough to form mature planetary systems so stars similar to our Sun are the best canditates - F and G type stars (of course, planets have been detected around pulsars and brown dwarfs so there are always exceptions to the rule). NASA's PlanetQuest website is the best source of a map of planets.--Sofsoldier 05:00, 10 July 2006 (UTC)

All in all the images used with this article are pretty good, but IMHO there's room for improvement. For one thing, my preference would be to have fewer artist's conceptions---there's certainly room for that sort of thing, but they're quite speculative. So I think we shouldn't have too many in a strictly factual article. Secondly, I'm not too happy with the image that illustrates gravitational microlensing. The thing is that there are TWO stars involved: the source star and the planet's parent star. The diagram fails to make that clear. Finally, I would like a diagram illustrating the radial-velocity (Doppler) method. I may try to make one myself, but if anyone has a good image on-hand that would be a good thing to add. Kevin Nelson 22:44, 22 July 2006 (UTC)

Planet naming

I edited the planet naming conventions. Extrasolar planets are not named by orbit, but by discovery date. A great example is the Gliese876 system (as in the article). The clostest, smallest body is designated "d," not "b" or "c."--Sofsoldier 05:07, 10 July 2006 (UTC)

Non-working or Non-English Links

It's nice to see external links to searchable databases of extrasolar planets. This would allow various user-driven search/sort criteria like sort by ascending distance from earth, etc.

Unfortunately one link points to a German language site: | searchable dynamic database of extrasolar planets and their parent stars

And another link points to a non-functioning server: | Extrasolar Planet XML Database

I found this searchable database, but it doesn't allow sorting by distance from earth: [5]

I found this one, which allows sorting by all criteria; not sure if it's appropriate to reference or not: Joema 03:30, 18 December 2005 (UTC)

http://vo.obspm.fr/exoplanetes/encyclo/catalog-main.php?mdAff=output#tc

Extrasolar Moons

Does anyone know of any Extrasolar moons? Any information will be helpful on this subject as I have not yet heard of any "real case" of an extrasolar moon. Maurice45 17:55 23 January 2006 (UTC)

I personally know of none, and moreover, I think at this point it is extremely unlikely that one has been detected. This should not be taken as evidence that other planets don't have moons, however; it's still not possible to detect even a planet the size of the Earth in almost all cases, let alone something smaller. So the selection effects rule out any confirmation or refutation of moons around other planets at this point. Motorneuron 22:08, 8 March 2006 (UTC)motorneuron

If an "exomoon" had been detected I'm pretty sure I would have heard of it. NASA's Kepler satellite may find some, but I doubt any will be found before it goes into operation. Kevin Nelson 19:02, 21 June 2006 (UTC)

It is assumed a moon of a planet would be much less massive than its host. We have only been able to detect down to about 7.5 Earth-masses. It is hoped astrometry could detect an orbiting moon but this is highly unlikely. The Terrestrial Planet Finder and DARWIN - orbiting infrared interferometers set to launch in the near future - could possibly be sensitive enough to detect large moons, but we will have to wait for the initial results to see just how sensitive these instruments will be.--Sofsoldier 05:04, 10 July 2006 (UTC)

So could the masses of currently detected planets actually include exomoon mass? A planet that seems to be 7.5 Earth masses could have a .5 earth mass moon and itself be only 7 earth masses. How could that be detected? DannyStevens 13:42, 23 August 2006 (UTC)
In principle, it does seem possible that the currently cited mass could include the mass of a moon. But mass estimates for exoplanets typically have pretty substantial error ranges, and I would expect that the mass of any moons would normally be less than the error range. The transit method, if performed with sufficient precision, would enable the detection of moons and enable an indirect estimate of their masses. Kevin Nelson 03:28, 27 August 2006 (UTC)

I deduced the existence of a moon inside the Mira star R Hydra. Supposedly it has since being swallowed up by R Hydra evolved into a protostar or a star. I wrote about my analysis of R Hydra and this hypothesis in the chapter "Intrastars" in my book "Making sense of Astronomy & geology" (2000) as well as in a less sophisticated chapter in the earlier, less sophisticated edition "Astrophysical discoveries" (1999). Dirk Bontes 17:21, 5 October 2006 (UTC)

Without buying your book, can you provide any data that supports your hypothesis? Sofsoldier

Data? You mean an observational fact that preferably can be observed repeatedly? It is called a light curve and the light curve graph of R Hydra can be found in most books about Mira type variable stars. Dirk Bontes 05:04, 21 November 2006 (UTC)

New Records

Today's announcement of the 4x earth mass rocky planet has been added, but looks like it will need to be added to the table under the following categories: smallest, and furthest from earth. I'll leave that to the experts as I may be wrong. Jafafa Hots 02:01, 26 January 2006 (UTC)

I have now done that. Kevin Nelson 08:18, 22 June 2006 (UTC)

Zeta Reticuli

I find it interesting that no planets have been found around the binary star system of Zeta Reticuli. There was a planet found in 1996 and added to the Extrasolar planets catalog, but it was removed a few days later. What's the odds that this would happen to a star system so caught up in Ufology? Interesting! Barney Hill 23:35, 26 January 2006 (UTC)

Van de Kamp and Barnard's Star

Is it worthwhile to add some history about Peter van de Kamp and his claim about a planet orbiting Barnard's star? http://www.public.asu.edu/~sciref/exoplnt.htm

Definitely. The article's coverage on earlier studies is almost nonexistent.--Jyril 13:07, 9 May 2006 (UTC)
I've added a little, but the article is already flagged as potentially too long. So I don't think a whole lot should be added about this aspect of the subject's earlier history.Kevin Nelson 04:47, 26 June 2006 (UTC)
We could add a sub-article on the history of the search for exoplanets and then link it to this one, thus providing the information but not elongating this article too much. Vsst 22:50, 31 May 2007 (UTC)

Methods

It doesn't talk much about how the transit method actually works, and how it can reveal the size of a planet. How exactly does that work? karlchwe

Good question, I updated the article. When the planet crosses its host star's disk, the star dims a bit (a couple of percent at maximum for a Sun-like star). If you can determine the star's diameter, you can estimate the size of the planet.--Jyril 15:09, 6 May 2006 (UTC)

Erroneous detections in "History" section?

It seems sort of strange that the first section ("History of Detection") discusses the spurious detection of the HD 114762 "planet" without discussing various other previous spurious detections. It seems to me that either there should be a whole paragraph there about the (lengthy) history of spurious detections, or else the discussion of HD 114762 should be cut out completely. Alternately maybe the section could begin by discussing the brown dwarf/planet distinction, since HD114762 evidently is a brown dwarf, but I'm not sure that's a good thing to have at the beginning of the section. Kevin Nelson 01:55, 21 June 2006 (UTC)

Reorganization of sections

I would like to do a fairly substantial reorganization as follows. First of all, note that the "Methods of Detection" section starts out by mentioning six methods. One might suppose that then there is one subsection per method, but instead that section contains ten subsections...potentially highly confusing. So I'd like to merge several subsections there. Next, I'd like to add a brand-new section about statistical properties of exoplanets. One of the main underlying questions there is whether and to what extent our own Solar System is unusual. Kevin Nelson 06:00, 24 June 2006 (UTC)

Deleted subsection about eclipse-minima timing method

Somewhat reluctantly, I deleted the entire subsection. It's good material, but it's about a method that so far has not been used successfully, that has attracted at most moderate enthusiasm from astronomers, that would only be applicable in rather limited situations, and that would not provide data of a sort much different than other methods. So since length of the article is a concern, I deleted it to make room for other material that seems of more central importance. Kevin Nelson 10:37, 24 July 2006 (UTC)

I recovered this material and put it in the new Methods of detecting extrasolar planets article. --Cuddlyopedia 06:00, 5 October 2006 (UTC)

Mysterious problem with reference numbers

I don't know what's going on, but all of a sudden the reference numbers got scrambled. It's as if some of the [1] tags are "double-firing" and creating two entries in the reference list at the end of the article. Then the first entry doesn't point back to anything in the article. The reference list then winds up much longer than it should be. I tried to revert but the problem recurs even when reverting to a previous version where it had NOT shown up. I've been working on this for more than an hour without much progress. You can see the problem for example in the 10:02 30 August 2006 version. The very first reference (to Marcy, Butler and Fischer) should be note 1, but it's listed as note 37. Then it turns out that there IS a note 1, but note 1 and note 37 are duplicates. Kevin Nelson 12:36, 30 August 2006 (UTC)

See Template talk:Cite web#Confused by bug. -- Jeandré, 2006-08-30t18:45z

WP:0.5 and FAC Nomination

I have nominated this page for inclusion in Wikipedia:Version 0.5. The way I see it, this is a failed FAC solely due to inline citation problems, which seems to have been fixed quite nicely. I would recommend that this article be re-nominated as a Featured Article Candidate.

There's still one section (General Properties) that is completely unsourced. And from my perspective, that is possibly the most important section in the article. Once that is fixed, I think it will be time to re-nominate the article for a Featured Article. Kevin Nelson 00:18, 1 September 2006 (UTC)
I am now nominating this article as a FAC. The previous problems identified with it appear to have been entirely corrected and in addition a wide range of other improvements have been made to the article. Kevin Nelson 07:36, 7 September 2006 (UTC)

"Planetary system or star system"

In the opening sentence, it's not clear to me what information is conveyed by "planetary system or star system" that is not conveyed by just "planetary system". The latter phrasing is more concise and, it seems to me, less confusing. The former phrasing might imply to some readers that some planets are in star systems INSTEAD of planetary systems, which is surely not an implication we want to make. Kevin Nelson 04:32, 9 September 2006 (UTC)

Thanks for the comment - that was me. The preceding text is equally confusing; at least currently, the 'or' statement clarifies the point. By not noting 'star system' – i.e., "a planet ... that ... belongs to a planetary system beyond the solar system" – there's an implication that the solar system is just a planetary system. For clarity, a possible rephrase is: "beyond that of the solar system" or "belongs to a planetary system beyond the solar system's planetary system" or perhaps "beyond the solar system (and) in another star system". Thoughts? Cogito ergo sumo 04:52, 9 September 2006 (UTC)

All right, I see your point. It seems to me that the opening of this article should preferably not hinge on the meaning of "Solar System" or on possible misconceptions about it. So what do you think of the following opening: "An extrasolar planet, or exoplanet, is a planet that orbits a star other than the Sun, and that is therefore beyond the Solar System." Kevin Nelson 07:39, 10 September 2006 (UTC)

Hello. I agree with you about not having the introduction hinge on notions of Solar System; however, given the topic matter, I believe it is important to somehow note 'planetary system'. So, as alternatives to the above, how about this:
OR
or similar. I can even see this being built into the 2nd or 3rd paragraph. Thoughts? Thanks! Cogito ergo sumo 08:06, 10 September 2006 (UTC)

I went ahead and made an edit that I think addresses your concerns. If you think there's still room for improvement, you can tweak it as you wish and I will check back here if you want to discuss it further. Kevin Nelson 07:35, 12 September 2006 (UTC)

Generally, it looks fine. Thanks! :) Cogito ergo sumo 08:19, 12 September 2006 (UTC)

Reference

There is a good review: Sozzetti A. (2005). "Astrometric methods and instrumentation to identify and characterize extrasolar planets". PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC 117 (836): 1021–1048. 

"Today's featured article" request questions

I went to Today's featured article/requests to try to get this article into the que to be listed as a "Today's featured article" sometime but I have to admit that I am rather mystified by the process. There is supposed to be an "adapted lead section"...should I just copy and paste the lead of the article as it now exists into that page with appropriate HTML tags like the other article leads on that page have? If so, then the main article may change while that "adapted lead" stays the same. I have spent a while searching for some document giving guidelines on this but haven't found anything. Kevin Nelson 09:18, 14 September 2006 (UTC)

I have seen several instances where the adapted lead that appears on the main page is different from the (newer) one in the article. Aran|heru|nar 09:53, 7 December 2006 (UTC)

Eccentricity of Extrasolar planets

In the following article: http://www.science.psu.edu/alert/Luhman9-2006-2.htm, a potential explanation is given for the puzzling eccentricities observed. This is only my second contribution, I would prefer to leave it in more experienced hands.

Added. --Cuddlyopedia 11:00, 28 September 2006 (UTC)

"orbiting stars other than the Sun" deletion

According to its Wikipedia article, the Solar System is defined as "the Sun and the retinue of celestial objects gravitationally bound to it". Consequently, an extrasolar planet - if it is not part of the Solar System - must by definition orbit a star other than the Sun. So I am deleting this phrase as redundant. Ribonucleic 16:47, 27 September 2006 (UTC)

Well - depending on which side of the controversy you come down on - an extrasolar planet could be a free-floating object not orbiting a star at all! But, I agree, the phrase was redundant, especially given the second paragraph. --Cuddlyopedia 05:10, 28 September 2006 (UTC)

Move 'Methods of detection' to its own article?

The present article is already longer than generally desired, and is only likely to get longer as new discoveries are made. That normally means it's time to see if there are any parts that can be hived off into their own article. 'Methods of detection' seems tailor-made for that, as it is self-contained and prone to technical detail. We can then have a short section here that references the new article and just gives short summaries of the methods. I suggest 'Methods of detecting extrasolar planets' as a title for any such article. Any objections, comments? If no objections within the next week (or longer if people think it appropriate), I'll make the change. --Cuddlyopedia 05:10, 28 September 2006 (UTC)

Agreed, the article does appear to be too long. The removed methods of detection should also be restored. Sdp1978 18:49, 29 September 2006 (UTC)
As no objection (and some support), new article created with detailed information copied from here, and summary created in its place. --Cuddlyopedia 20:35, 4 October 2006 (UTC)
You forgot to update the references Sdp1978 22:53, 4 October 2006 (UTC)
I've initialised the references in the new article. (Thank you.) Or did you mean something else? I've also added the material on detection methods Kevin Nelson deleted here in July. --Cuddlyopedia 06:00, 5 October 2006 (UTC)
Good Work! --Sdp1978 14:35, 5 October 2006 (UTC)

Alternative interpretation of radial velocity and transit observations

In my book I have proposed a different interpretation of the periodicity in the spectral shift of these stars, as due not to the Doppler effect and radial velocity changes, but as due to the Zeeman effect.

("Making sense of astronomy & geology" (2000) as well as in a less sophisticated chapter in the earlier, less sophisticated edition "Astrophysical discoveries" (1999); chapter: "Eta Carinae, the illusion of exo-planets, and the Zeeman effect".)

The brightness of the star and these magnetic effects are causally related, hence the supposed transit by a planet of some of these Zeeman effect stars is an illusion as well. Dirk Bontes 17:36, 5 October 2006 (UTC)

The radial velocity hypothesis can be proven easily - and my Zeeman effect hypothesis disproven simultaneously - by supplying a photograph of the planetary disk of such an exoplanet. Nobody has made such a photograph and according to my Zeeman effect hypothesis nobody ever will. There is no conclusive evidence - no observation - that these radial velocity exoplanets in fact exist. Indeed, the "extremely odd" orbits of some of these alleged exoplanets indicate that they do not exist. Dirk Bontes 10:20, 20 November 2006 (UTC)

I would be curious to see any computer simulations you have done in regards to these orbits. Do you have any screen grabs of simulation results? Sofsoldier

Computer simulations? Ever hear of the phrase "Garbage in, garbage out"? Computer simulations do not prove anything. Please stop boring me with your computer simulation pseudoscience.

Unless our solar system is not a run of the mill solar system, all planets within the relative distance of the orbit of Venus - in our solar system the planet Mercury - just like Mercury must have an extremely excentric orbit that precesses fanatically as required by the general theory of relativity. The alleged "hot Jupiter exoplanets" orbiting as close to their star as to nearly touch them, all have perfectly circular orbits that are not visibly precessing. That contradicts what we know about the extremely excentric and rapidly precessing orbit of such a planet (Mercury). Ergo these exoplanets cannot and do not exist.

I challenge anyone to provide a photograph of the planetary disk separated from its parent star of one of these alleged exoplanets. That will be real science. It will never happen. Dirk Bontes 05:37, 21 November 2006 (UTC)

Why photographs? The resolution of most telescopes does not permit that yet. It's also unnecessary. There are much more refined ways to detect the presence of exoplanets and planetary disks than just by photographing visible light. Besides, since your "theory" is pretty much of the fringe variety, Wikipedia is in no way obligated to mention it. Motormind 20:28, 7 December 2006 (UTC)

So you think that photographic evidence is unnecessary, Motormind? That is also the position of the people who claim that the Moon is a large Swiss cheese with holes in it (presumably made by Moon mice). Science it is not. You say: "There are much more refined ways to detect the presence of exoplanets and planetary disks than just by photographing visible light". You are very vague. Like what much more refined ways? (Please, please do not bore me with fairy tales about interpretations of radial velocity and transit observations. Interpretations are not facts.) Show me a photograph. Show me solid evidence instead of pseudoscientific Swiss cheese. Dirk Bontes 02:31, 14 December 2006 (UTC)

Is extra solar planet a misnomer?

Under the new definition of a planet, is the term Exoplanet preferable above Extrasolar Planet? Hopquick 17:46, 13 October 2006 (UTC)

The new definition is only for Solar system planets. 'Extrasolar planet' and 'exoplanet' are synonymous, the first being more "formal".--JyriL talk 19:05, 13 October 2006 (UTC)
Just could'nt resist it: it's the IAU definition that is a linguistic and scientific misfit - just disregard it! An exoplanet is a planet that is not in our solar system, i.e. a extrasolar planet - perfect terms both, no doubts, not hard to identify them, no risk for misunderstandings. Regarding all confusions coming from the IAU planet definition - let's just wait and see if they're able to improve it from the level of ridicule. Rursus 22:00, 7 December 2006 (UTC)

Anymore articles?

Does anybody know where I can find more articles on astronomy? If you do email them to [address removed]. Thanks.75.44.152.183 03:48, 5 December 2006 (UTC)Holly Brown.

Wiki has also an Astronomy portal: http://en.wikipedia.org/wiki/Portal:Astronomy xeryus 00:35, 7 December 2006 (UTC)

Awesome article

This article is very awesome and interesting to read and I have it now on my watchlist<br?http://en.wikipedia.org/wiki/User:Berniethomas68 01:09, 7 December 2006 (UTC)

Wrong Picture

The first picture is displayed as George W. Bush and the caption does not match. 71.247.90.213 02:17, 7 December 2006 (UTC)

You are currently viewing a revision from hours ago. The problem has been fixed and should show up normally if you reload the page. Gdo01 02:19, 7 December 2006 (UTC)

LEAD tag

Please clean up the lead paragraph. FrummerThanThou 02:50, 7 December 2006 (UTC)

I don't see anything that goes against the Lead section guidelines. Titoxd(?!?) 03:10, 7 December 2006 (UTC)

Opening sentence

While I understand that the term 'Solar System' refers explicitly to our own star system (deriving its name from the Sun's Latin Sol), I fear that the average reader may associate the term 'solar system' with that of any star and corresponding orbit(s). Thus, I added "(i.e. orbits a star other than the Sun.)" to the end of the opening sentence to clarify that these planets are not simply planets without orbits, but with orbits around stars other than the Sun. I'm not sure this is the best grammatical way to do it, but I think such a clarification is needed. —Aiden 04:04, 7 December 2006 (UTC)

Since such objects do not satisfy the working definition of "planet" adopted by the International Astronomical Union

Any exoplanet do not satisfy the definition--Planemo 08:20, 7 December 2006 (UTC)

Yep, I was about to add that myself. That definition is only for planets that orbit our sun, so the reason for excluding those from this article doesn't make sense. as no extrasolar planets would fit that definition. VegaDark 08:25, 7 December 2006 (UTC)
There are two different definitions at issue. The recent redefinition that excluded Pluto, which is probably the one you are thinking of, does indeed apply only to the Solar System. As that was officially adopted, it no longer counts as a mere "working definition." But there is another working definition for exoplanets, as can be found in the external link under footnote 2. That latter definition is the one that excludes "free-floating" planets. This is certainly a confusing point, and the lead could probably do a better job of explaining it. In particular, I'm not too sure about the wikilink to the article about the first (Solar-System-only) planet redefinition. Kevin Nelson 22:11, 7 December 2006 (UTC)

Habitable zone

Hasn't the old concept that the habitable zone is small been under attack recently? I remember reading an article on new scientist but I'll be damned if I can find it right now --Energman 09:01, 7 December 2006 (UTC)

This question has been disputed for decades and though there seems to have been a bit of convergence of opinion to an intermediate value, the question is far from settled. The figures in the article actually show relatively large habitable zones, stretching most of the way from Earth to Mars and to Venus. Kevin Nelson 23:11, 7 December 2006 (UTC)

Cyrillic Text in First Paragraph?

What's up with the Cyrillic text in the first paragraph? Doesn't seem to fit an English-language wiki. Bob99 15:43, 7 December 2006 (UTC)

Someone reverted it as a good-faith edit made by an IP user. It shouldn't have been there, though. Nishkid64 15:44, 7 December 2006 (UTC)

Where did the article go?

The article is now blank. Is it just my computer, or has someone deleted every last word? —The preceding unsigned comment was added by 76.185.18.21 (talk) 23:41, 7 December 2006 (UTC). I've also noticed that if you try to edit, or look at the last update, everything is normal. What is going on?

  • Try to clear your browser cache and then refreshing the page. Sometimes the browsers insist of showing the cached (and inthis case, outdated) version - Skysmith 09:29, 8 December 2006 (UTC)

Penis Vandalism

It seems that there's a repeating jpg of a penis here. I can't seeem to get rid of it, since it's not showing up.

It's marked under 'see also'.

Any ideas? --64.233.226.150 18:00, 9 December 2006 (UTC)


Got it. Nice job, guys!

Notable Extrasolar Planets

I think it would be a good addition to add the closest Extrasolar planet to the earth which i believe is HD 189733b. I'd do it myself but I don't know the proper way to atribute sources in wikipedia.

What sources do you have? Tell us everything you know about it, and we'll add it in for you. enochlau (talk) 08:28, 10 December 2006 (UTC)

I read it at this press release: http://solarsystem.nasa.gov/news/display.cfm?News_ID=13897 Though I don't know if press releases count as valid source material or if it is still up to date. Also I have read that there are other suspected but unconfirmed planets that are closer.

I believe, it's Epsilon Eridani that should be added. It is confirmed and seems to be the closest discovered - 10.4 LY (BTW, compared to 63 LY of HD 189733b). See List of extrasolar planet extremes. Cmapm 03:25, 14 December 2006 (UTC)

Why was the history of detection section deleted?

Can't find any reason for this deletion. It seemed like a good section to me. —The preceding unsigned comment was added by Grant Gussie (talkcontribs) 21:41, 11 December 2006 (UTC).

It was vandalism, fixed now. Partly my fault for not realising what had happened (another anon removed the vandal text but didn't add back the missing section). Quarl (talk) 2006-12-14 00:03Z


Status of 2M1207 b

The caption currently says that there is debate as to whether 2M1207 b is a planet or brown dwarf. I am unaware of any published argument that it is a brown dwarf, although Mohanty et. al. (preprint accepted by Astrophysical Journal) do estimate its mass at 8 M_J, which is close enough to the mass boundary for a bit of caution to be in order. If anyone has further information about a debate on the subject I would be interested to hear about it, but if I don't get any further information I will change the caption back to indicate that it is believed to be a planet. Kevin Nelson 11:01, 9 January 2007 (UTC)

Lack of discoveries

Why didn't we discovered any new planets for more than three months since October 9, 2006 (Columbus Day)? Will any new planets will be discovered this month? Cosmium 19:52, 13 January 2007 (UTC)

Well, the announcements of discovery usually come with confirmation, so probably many candidates have been found, but reporting false alarms isn't particularly useful, is it? They'll come.--Planetary 01:00, 30 January 2007 (UTC)
Perhaps we found all of them already :P enochlau (talk) 01:03, 30 January 2007 (UTC)
Likely never.--Planetary 01:07, 30 January 2007 (UTC)

I found that four new planets were finally discovered already in February, in which planets haven't been discovered for nearly four months. I am happy about that! Cosmium 17:57, 24 February 2007 (UTC)

HD 188753 A

A preprint by Eggenberger, Udry et. al. is now out in which they emphatically assert that they can find no evidence of the alleged planet around this star. The paragraph about this alleged planet has already been removed from the article, but I think it would be a good idea to rewrite it and put it back in as a disputed planet. First of all, I'm not sure that the existence or non-existence of the planet is entirely settled; Konacki may come back with a rejoinder. Secondly, this alleged planet attracted quite a bit of notice when it was first announced, so I think it would be a good idea to still have something about it. Kevin Nelson 10:14, 22 February 2007 (UTC)


I disagree. This planet is not listed in catalogs like the peer-reviewed Catalog of Exoplanets or the Encyclopedia of Extrasolar Planets, it existence would make no sense under our current understanding of planet formation, its separate page is still up for the interested, and this is already a long article. Enfolder 15:34, 22 February 2007 (UTC)

Encyclopaedia of Extrasolar Planets does indeed still list the alleged HD 188753 A planet, albeit under "Unconfirmed, controversial or retracted planets." It also has a link to a reply by Konacki in which he defends his work. So this is not a retracted planet. In my personal opinion, Eggenberger et al are very probably right and the planet is nonexistent. But as recognized experts continue to disagree I think it is reasonable for the article to continue to have a paragraph about this in which the dispute is discussed. Kevin Nelson 10:54, 23 February 2007 (UTC)

age for PSR B1620-26c

Minor point. The caption of the "artist's impression" of PSR B1620-26c states that the planet is "over 12.5 billion years old," while the text just to the left says that the planet is "13 billion years old." The article on the planet gives a figure of 12.7 billion years. Of course there is going to be some uncertainty in the age, but it would be less confusing if a consistent value is chosen for the text. Perhaps the 12.7 billion from the article? Is anyone familiar with the best guess for the age? Wesino 15:11, 11 April 2007 (UTC)

HD 209458 b - Atmospheric water vapor

The latest news on HD 209458 b, namely HD 209458 b#Atmospheric water vapor should be added to this article. Carcharoth 13:07, 12 April 2007 (UTC)

Agreed. There is a to do list where you can place your suggestions. Perhaps it would go on a section on atmosphere spectra in general. Sdp1978 13:19, 12 April 2007 (UTC)

Thanks. Noted on the to-do list. Carcharoth 14:50, 12 April 2007 (UTC)
Think that could go in the final paragraph of the general properties section. Which of course could be updated. Sdp1978 15:09, 13 April 2007 (UTC)

Link to HARP

The link to HARP in the new item about Gliese 581c doesn't appear to provide any info about this technique, so unless I am mistaken the link ahould be deleted. Robin Scagell 07:18, 25 April 2007 (UTC)

  • Additional link added to sentence leading to subsection of exoplanet detection methods. Abyssoft 15:27, 25 April 2007 (UTC)

SIM PlanetQuest

Hello everybody. I have undertaken the expansion of Space Interferometry Mission (see diff) dating back to November 2006. It is currently undergoing a peer review as well, I have left additional comments on the talk page.

I am wondering what this article is missing or where it needs work. I have completed two copy edits myself but fear that I may no longer be able to do much in that area. Any comments would be appreciated. IvoShandor 18:19, 27 April 2007 (UTC)

You could work through the to-do list at the top of the page.--Sdp1978 09:59, 28 April 2007 (UTC)
Eh? Anything there besides a recent peer review I put just FYI. I was looking more for commentary from unaffiliated readers. IvoShandor 11:32, 28 April 2007 (UTC)

Extrasolar planets in our galaxy

I estimate that 1080 billion extrasolar planets orbit 240 billion stars. BlueEarth 18:57, 5 May 2007 (UTC)

That's great. Zazaban 23:05, 6 June 2007 (UTC)

Notable(?) exoplantes

IMVHO, some of entries in "Notable extrasolar planets" chapter are not so notable. Expecially Corot-exo-1b is just another hot jupiter. In light of recent discoveries, some of previous entries must be dropped, for example Gliese 876 d (who cares about second lightest known exoplanet? Should be replaced with new, actualised entry in category "lighest known exoplanet"). In other words, list of notable exoplanet must be not only filled with new entires, but also revised as whole. --83.144.95.66 14:12, 26 May 2007 (UTC)

Do we even need all that information? Zazaban 23:02, 6 June 2007 (UTC)

I basically agree. I think that section is now just too long. The space would be better used for more general information. I would like to keep Gliese 876d however. The planets at the low end of the mass range are all especially interesting because they are getting down into the Earthlike range. Also, I would like to suggest that this section be arranged in terms of planets rather than years. Right now, we can have several different paragraphs for the same planet scattered around the section, and that just doesn't strike me as a very good way of organizing it. Kevin Nelson 12:18, 19 July 2007 (UTC)

Gliese 581c

The article currently argues that it has been "shown" that this planet lies outside the habitable zone. However, that's been done on the basis of an as-yet unpublished preprint, which has not yet been subject to peer review (though the preprint is the work of widely published researchers in the area, by the looks). Should the claim to be outside the habitable zone be toned down somewhat, say to "some researchers believe that..." for now? --Robert Merkel 02:59, 7 June 2007 (UTC)

"Ignorance is bliss."

The planet gets 5 times the heat (Insolation) the Earth does at perihelion, which is more than twice the irradiance of Venus also. That is a very simple calculation and has not been in dispute; If there is a planet there (binary/gasdwarf/cthonian/whatever) it is too hot to be habitable.
There are other references there you are ignoring
(http://arxiv.org/abs/0712.3219v4);
"The super-Earth Gl 581c is clearly outside the pHZ"
I trust these published scientists, so please find a different fantasy. GabrielVelasquez (talk) 21:31, 22 June 2008 (UTC)


The 5x figure is not mentioned in van Bloh et al.; neither is a runaway greenhouse effect. In fact, those authors do not examine the habitability of Gl 581 c in detail; it's basically assumed to be uninhabitable. Selsis is a better reference here, but they don't mention the 5x figure either. Furthermore, the 5x figure is only correct during the periastron passage, and is not representative of the overall insolation the planet gets. Editing accordingly. J. Langton (talk) 13:20, 24 July 2008 (UTC)

HD 154345b

I have removed the description of this planet from the "notable" section of the article, because it was completely unsupported by the citation, and inaccurate to wit. This object has been mentioned once just in the literature -- in Wright et al. 2007 -- which showed that the orbit is so far unconstrained.

Image

It's somewhat confusing to have Image:Phot-14a-05-preview.jpg twice in the article, I'd say... can we fix this? --Ouro (blah blah) 06:26, 11 July 2007 (UTC)

Formula for radius and temperature

Here's the formula for calculating radius and temperature for extrasolar planets. You should add calculated r & T to extrasolar planet articles.

 R_{planet} = \sqrt{\frac {\sqrt [3]{M_{planet}} \times \sqrt {R_{star}}} {\sqrt [4]{a}}}

 T_{planet} = \frac {\sqrt [4]{L_{star}} \times 256} {\sqrt{a}}

where:
M_{planet} is the mass of the planet
R_{planet} is the radius of the planet
T_{planet} is the temperature of the planet
a is the semimajor axis
R_{star} is the radius of the star
L_{star} is the luminosity of the star

Note: After finding the radius, you should find density by formula m/r³ and gravity by formula m/r². The radius of planets can only be calculated orbiting the main-sequence stars. Giants and subgiants have grew larger in radius and does not grow planets in radius because of the expanding star's radius.

--BlueEarth 18:05, 24 July 2007 (UTC)

Where did you get those from?!? I fail to grasp how the radius of a planet can be dependent on the radius of its parent star or of its semimajor axis. (Not to mention that density also needs to be factored in.) The formula for the temperature of the planet looks more reasonable. However, it has no units, and the use of semimajor axis instead of (weighted) mean distance to the star is highly suspect. Ben Hocking (talk|contribs) 18:20, 24 July 2007 (UTC)
I tried different set of radius formula for trying to find radius of the planet Gliese 581 c until I'll get exactly 1.5 RE as it was referenced. I made the temperature formula by trying to calculating the temperature of extrasolar planets with changing formula until I'll get exact value and accepting the formula from calculating effective temperature of Mars and Jupiter. BlueEarth 19:54, 24 July 2007 (UTC)
A general formula for the radius would be:R_{planet} = \sqrt [3]{\frac{3M_{planet}}{4 \pi \rho_{planet}}} where \rho_{planet} is the density of the planet. If your units are cgs, \rho_{planet} might not differ significantly from 1 (the density of water in g/cm3). There will be no simple way to deduce the density (except for using the radius and mass) as some planets are rocky, gaseous, etc. The temperature of the planet is also a little more complicated than what you have there. (I'll have to look into that one, as I don't have it off the top of my head.) Ben Hocking (talk|contribs) 22:07, 24 July 2007 (UTC)
A planet's density is not only affected by the material it is made of, but also by gravitational pressure which is significant for giant planets (gas giants like Jupiter, brown dwarfs and low-mass red dwarfs are all about the same size despite their highly different masses).— JyriL talk 22:52, 1 August 2007 (UTC)

This radius formula is nonsense. First off, the author claims it is based on the properties of a planet for which the radius isn't actually known, secondly it is not dimensionally consistent, thirdly it doesn't actually work for our solar system, so expecting it to work for every other planetary system is ridiculous. Look, if the radius and temperature of an extrasolar planet are unknown, just don't put them in the infobox. This is an encyclopaedia, it is a summary of what is known. If something isn't known, then we shouldn't pretend it is. Chaos syndrome 21:32, 29 July 2007 (UTC)

Theoretical surface temperature of a planet is

T = T_\star \sqrt[4] { \frac {1 - A} { 2 } } \sqrt { \frac {R_\star} {r} }

and for a rapidly rotating planet (when the amount of emitted radiation is equal across the whole surface)

T = T_\star \sqrt[4] { \frac {1 - A} { 4 } } \sqrt { \frac {R_\star} {r} }

A is the planet's Bond albedo, which obviously is unknown for extrasolar planets, and r is its orbital distance. R_\star is the star's radius. When we take atmosphere into account, things like greenhouse effect and heat currents guarantee the values given by the equations become wildly off-mark. For example, based on these Venus would be slightly cooler than Earth because of its very high albedo. — JyriL talk 22:52, 1 August 2007 (UTC)

Derivation

...(copied from Gliese 581 c)... see these articles (already in the encyclopedia) for the relevant astronomical formulae:

This chart shows possible surface temperatures in Celsius for the planet based on possible Albedo and Emissivity.
















Inclination and true mass

How can I calculate true mass when inclination is known? BlueEarth 16:54, 26 July 2007 (UTC)

The formula is

M = \frac {M_{min}}{sin(i)}

where M_{min} is the minimum mass derived from RV measurements and i is the inclination in degrees. Note that we don't need this formula since the only cases when inclination is known (transiting planets) the true mass is already given. — JyriL talk 22:19, 1 August 2007 (UTC)

Notable extrasolar planets.

Should this section be split off into it's own article? Zazaban 22:32, 28 July 2007 (UTC)

It's definitely arguable - i.e., I have mixed feelings about it. Also, it needs some work - there's a lot of bad sentence structure, etc. I'll probably come back to it soon. Ben Hocking (talk|contribs) 23:41, 28 July 2007 (UTC)
Agreed, some of the planets should not even be there. Zazaban 21:45, 30 July 2007 (UTC)

I'll say leave it in extrasolar planet article as section. BlueEarth 19:20, 29 July 2007 (UTC)

I'd suggest to have its own article, especially as the list is bound to grow when they find water, a moon etc. In this article, reduce it to something much smaller. E.g.
The first verified exoplanet was PSR B1257+12, which orbited a pulsar. 51 Pegasi b was the first found orbiting a normal star and the first Hot Jupiter. HD 209458 b was the first planet seen transiting its parent star, confirming that the radial velocity measurements was finding real planets and not stellar oddities.
And so on for everything of note. The original text would all be at the new article. --GwydionM 18:11, 7 August 2007 (UTC)
That section deserves serious pruning. Most of the "notable" extrasolar planets don't really deserve a mention. The overhyped HAT-P-1b isn't as big as originally thought and TrES-4 is larger than it anyway. There's nothing special in TrES-1 and Corot-exo-1b. HAT-P-2b is less massive than XO-3b. There are doubts about the existence of HD 188753 Ab. SWEEPS-10 remains unconfirmed. There is no reason to include HD 28185 b and HD 70642 b. HD 28185 b orbits further than Earth a star that is less bright than the Sun and HD 70642 b... well, any planet that can have large icy satellites can fulfill that requirement. Why it and not 47 UMa b for example? — JyriL talk 09:41, 26 August 2007 (UTC)

Catalog of Nearby Exoplanets

This website is the best exoplanet listing websites. It has most frequently changed parameters for planets, and hence most recently. It is best to use this site to update parameters in extrasolar planet articles and list of confirmed extrasolar planets with the exception of Mu Arae, 55 Cancri, 47 Ursae Majoris, and 14 Herculis planets, which is cited from the Extrasolar Planets Encyclopaedia. BlueEarth 21:34, 3 September 2007 (UTC)

Semi-amplitude

How can I calculate semi-amplitudes for extrasolar planets using planet mass, planet-star separation, and star mass? I knew that semi-amplitude is how fast the star wobbles, usually in meters per second (m/s). The more massive the planet is, the faster the star wobbles, hence the higher the semi-amplitude is. The greater planet-star separation or more massive the star is, the slower the semi-amplitude is.

Is this right: K = 30.87 \times {\sqrt[1.5]{M_{planet}} \div \sqrt[2.5]{a} \over \sqrt{M_{star}}} Note: 30.87 is the semi-amplitude of one Jupiter-mass planet that orbits at one astronomical unit around one solar-mass star.

--BlueEarth 00:32, 9 September 2007 (UTC)

Tabular firsts

I've merged the following table into the article, from List of planetary extremes, (these aren't extreme...) 132.205.44.5 23:10, 12 September 2007 (UTC)

===Discovery firsts===

Title Planet Star Year Notes
First planet discovered PSR B1257+12 B, C PSR B1257+12 1992 first extrasolar planets discovered
Note 1: The planet around Gamma Cephei was already suspected in 1988.
Note 2: HD 114762 b was discovered in 1989, but was not confirmed as a planet before 1996.
First discovery by system type
First planet around a solitary star PSR B1257+12 B, C PSR B1257+12 1992 first extrasolar planets discovered
Note 1: HD 114762 b was discovered in 1989, but was not confirmed as a planet before 1996.
First free-floating planet discovered S Ori 70 n/a 2004 has mass of 3 MJupiter, needs confirmation
Note: Free-floating objects are not usually considered planets.
First planet in a multiple star system discovered 55 Cancri b 55 Cancri 1996 55 Cnc has distant red dwarf companion
Note 1: The planet around Gamma Cephei was already suspected in 1988.
Note 2: Gamma Cephei is the first relatively close binary with a planet.
First planet orbiting multiple stars discovered PSR B1620-26c PSR B1620-26 1993 orbits pulsar - white dwarf pair
First multiple planet system discovered PSR 1257+12 A, B, C PSR 1257+12 1992 a pulsar planetary system
First planet in star cluster PSR B1620-26c PSR B1620-26 1993 located in Globular Cluster M4
First discovery by a method
First planet discovered using the pulsar timing method PSR B1257+12 B, C PSR B1257+12 1992
First planet discovered by radial velocity method 51 Pegasi b 51 Pegasi 1995
First planet discovered by transit method OGLE-TR-56 b OGLE-TR-56 2002
First planet found by gravitational lensing method OGLE-2003-BLG-235Lb OGLE-2003-BLG-235L/MOA-2003-BLG-53L 2004
First discovery by star type
First pulsar planet discovered PSR B1257+12 B, C PSR B1257+12 1992
First known planet orbiting a Sun-like star 51 Pegasi b 51 Pegasi 1995
First known planet orbiting a red dwarf Gliese 876 b Gliese 876 1998
First known planet orbiting a giant star Iota Draconis b Iota Draconis 2002
First known planet orbiting a white dwarf (confirmed 2003) PSR B1620-26c PSR B1620-26 1993
First known planet orbiting a brown dwarf 2M1207b 2M1207 2004
first directly imaged planet
First free-floating planet discovered S Ori 70 n/a 2004 has mass of 3 MJupiter, needs confirmation
Note: Free-floating objects are not usually considered planets.
Firsts by planet type
first cool, possibly rocky/icy planet around main-sequence star OGLE-2005-BLG-390Lb OGLE-2005-BLG-390L 2006
Other firsts
First transiting planet HD 209458 b HD 209458 1999
Note: OGLE-TR-56 b is the first planet found by transit method.
First directly imaged planet 2M1207b 2M1207 2004

The planet count as per reference 1

The total count of confirmed exoplanets has been edited a lot recently following the reference at http://exoplanet.eu/catalog.php. Generally we've been matching the count at this reference, reverting misinformed or spurious edits and updating in line with updates to the source. Recent edits have taken a new line on this- totalling only confirmed exoplanets with a mass < 13 MJ and referencing the same source with a caveat comment next to it.

My issues with this are: firstly, that the inclusion criteria at the source already consider a certain margin of error regarding mass. Further, objects above 13 MJ are included only if they are orbiting a star with another companion of lesser mass (and are therefore likely to have accerated from similar material). The 13 MJ upper limit on planets is not an absolute since, by my admittedly limited understanding, mass alone is not sufficient for the object to be considered a fusor. Finally, the figure will be far harder to keep updated if rather than simply matching the figure at a curated list, we will need to go through the list to check masses before incrementing the numbers. Right now I'm happy to leave it to people who know better, but thought it might be useful to discuss this. DoktorDec 11:41, 15 September 2007 (UTC)

Thoughts?

According to planetary mass type, 13 MJ is the upper limit for planetary-mass object. That's why I exclude these objects with more than 13 MJ. In my own Microsoft Word documents, I exclude these objects. Objects with over 13 MJ don't consider planets, they are considered brown dwarf. BlueEarth 18:36, 15 September 2007 (UTC)

There is no proven "extrasolar planet"

This page should reflect the fact that there is no proven extrasolar planet. If one views a planet as a naturally evolved, i.e. condensed from a star forming nebula, object, there is zero evidence that can be used to assert that these objects are indeed *planets*. The surveys that use light frequency shifts can assert a "mass" of an object -- however they cannot assert it is a planet because they did not observe its formation. It could just as equally be a "borg cube" Jupiter Brain, whatever... And so to be completely accurate it should be labeled a "putative planet". Similarly observations based on occultation can only lay claim to the diameter of an object (or coorbiting objects). They have no concrete proof of a "planet". The assumption of extrasolar planets rests upon the assumption that the rest of our galaxy reflects our small solar system and it must be completely dead (other than the Earth). This is an anthropocentric perspective which should not be accepted in an Encyclopedia. Because we exist, it is clear that evolution to higher states of being is not impossible. The documentation by Lineweaver's group that most of the Earth's in our galaxy are older than we are points out the need to consider than extrasolar "planets" may not be natural but may instead be engineered constructs. If you cannot *prove* it is a planet you should not be writing about it as a given assumption.

"Putative extrasolar planets" is reasonable. "Extrasolar planets" is not.

Robert 11:08, 6 November 2007 (UTC)

This makes sense. But the sources call them planets, so we call them planets. I agree with you, but we follow the sources. Zazaban 03:37, 10 November 2007 (UTC)

There are no exoplanets!

Because they may at most be Extra Solar Planetary Mass Objects! A planet must orbit around Sun, thus there is nothing such as Extra Solar ones. I propose, in the spirit of astronomer culture that we invent an abbreviation instead of this "planemo" monstrosity, namely ESPMO, which matches SSSB very well, and then we name our eyes humanoid vision sensors HSV, looking through our tubular light enhancement devices TLED at the virtual surface of heaven VSH, making observation aided conclusions OAC:s, ... Said: Rursus 10:24, 10 November 2007 (UTC)

I personally find the idea that planets can only orbit the sun to be idiotic and unbelievably self-centred. Astronomers do call them planets, so I don't think this will make it into the article. Zazaban 19:45, 10 November 2007 (UTC)

Well, while I personally think that the definition of planet should be: 1.

   * is in orbit around a star,
   * has sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and
   * has "cleared the neighborhood" around its orbit.

It is unfortunately

   * is in orbit around the Sun,
   * has sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and
   * has "cleared the neighborhood" around its orbit.

which means technically, at the moment, there are no planets outside the solar system. The definition of an exoplanet is: 1. An object at least the minimum size of what something in the solar system has to be to be considered a planet and that is not big enough to fuse deuterium However, they are not planets outside the solar system but instead a different class of objects all together. So there are exoplanets, but exoplanets aren't planets outside the solar system but a different classification. Well, according to this: http://www.dtm.ciw.edu/boss/definition.html 68.175.106.168 20:33, 14 November 2007 (UTC)

I would suppose an extra paragraph about the definition of the word planet concerning extrasolar planets. The IAU is an extraordinary example for discrepancy concerning word definitions! Here is the IAU definition for planets which is, as said above, in orbit around "the Sun". There is, however, no definition of "the Sun". It could as well mean "its own sun" as well as "our sun" also called SOL in astronomy, but not in the planet definition (which makes it scientificly simply unknown which definition is ment). But that's not the only problem! Another FAQ page of the official IAU website clearly shows that the IAU isn't even sure about these definitions by itself. So for example, this FAQ page of the official IAU website is titled "Planets around other stars" where they shouldn't be called planets at all according to their own definition of the word "planet" if they are orbiting another sun (if SOL is realy ment with the words "the Sun" in the planet definition). On the other hand, the phrase "Extrasolar Planet" could well be an extra definition as is the phrase "dwarf planet" and could as such not-yet officially defined phrase be used for planetary objects around other suns! But, as it should be assumed that SOL is ment with the words "the Sun" in the planet definition, the word "planet" should probably not be used by itself for planetary objects around other suns. This may seem strange, but as this is an official encyclopedia it should stick to the official definitions, even if many of us and the astronomers think it is "stupid". If the most astronomers at the next IAU meeting will not leave the meeting early (as it was at the last meeting when the planet definition resolution was passed), they may be able to correct their mistake, if they think it is one. But since the phrases "Extrasolar planet" and "planetary object" are not yet officially defined by the IAU, they still can be used for planetary objects around other stars! So it could not be said, there are no "Extrasolar planets" since the IAU has proofen with its own "dwarf planet" definition that there can be used phrases with the word "planet" in it, without meaning "planets" by the definition of the IAU. Still, there should be an extra paragraph about this highly complex subject! People should know that these objects around other stars are not "planets" by official definition of the IAU, but still can be called "Extrasolar Planets". Greetings, ColdCase 22:34, 14 November 2007 (UTC)

HD/Henry Draper Catalogue

This BBC article mentions conventions of planet-naming -> . I wondered whether someone could confirm that the 'HD' in many exoplanets names is derived from 'Henry Draper Catalogue'. maxrspct ping me 19:33, 13 January 2008 (UTC)

Yes, that's correct. Kevin Nelson (talk) 08:26, 9 August 2008 (UTC)

Types of extrasolar planets

Shouldn't there be a list of the various types of informal classification used to group extrasolar planets, such as hot Jupiter, super-Earth or hot Neptune? Serendipodous 20:51, 29 January 2008 (UTC)

Yes, it should. I'll might add informal groups of extrasolar planets any time soon. BlueEarth (talk) 00:13, 30 January 2008 (UTC)
If you find a list with the types for each of the extrasolar planets post a link please. The only one I could find was at the planetquest application, but I don't think it's been updated for some time. Raydekk (talk) 11:36, 16 March 2009 (UTC)

Another milestone ?

[6] The organic molecule methane has been detected in the atmosphere of a planet orbiting a distant star. The latest rumours say it concerns the gas giant HD 189733b, 63 light-years away, in the constellation Vulpecula.The discovery was made with Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS).Although the planet is too hot to support life as we know it, the finding demonstrates the ability to detect organic molecules spectroscopically around Earth-like planets in habitable zones around stars.NASA will hold a media teleconference at 18:00 GMT on Wednesday, 19 March, to report this unique discovery.

Any New High Quality Pictures of Exoplanets taken Yet?

Hey guys good to see a good discussion thread here. Does anybody know if there are any HQ pictures of exoplanets taken slightly close? You know where you can see what they look like? —Preceding unsigned comment added by Blueknightex (talkcontribs) 12:13, 8 May 2008 (UTC)

Once its gets fully published I think it could be listed in notable list.--Molobo (talk) 00:14, 16 March 2008 (UTC)

Thank You very much Blueknightex (talk) 12:17, 8 May 2008 (UTC)

Another one: Planet is 3x Earth's size

See Planet 3x Earth's size found around Brown Dwarf Star. Can this one be added? 65.173.105.197 (talk) 22:02, 3 June 2008 (UTC)

It was added to the database at reference 1 (http://exoplanet.eu/) on the 2nd of June. Added to this article on the same day. DoktorDec (talk) 19:01, 4 June 2008 (UTC)


Embedded Planets

If planets occur around intermediate mass stars (one or two solar masses) then some time during evolution they may be engulfed by a stellar wind or an expanding envelope as the star evolves into a red giant. Interaction of the outflowing material may have an observable interaction with the planet. Shock structures resulting from gravitational accretion drag, geometric drag and accretion might be observed at luminosities up to 10 to the 23rd W (.001 solar luminosity). For a planet with the mass of Jupiter, the shock temperatures lead to collisional cooling of the gas and to emergent UV line radiation at the source. If plasma conditions are realized and the planet has a magnetic field then there is the possibility of the radiation being pulsed by a magnetospheric gate process. These processes may lead to a method of indirect detection of planets. {http://adsabs.harvard.edu/abs/1981JBIS...34..494J} {http://adsabs.harvard.edu/abs/1999MNRAS.304..925S --aajacksoniv (talk) 10:45, 6 September 2008 (UTC)

First picture of a likely planet around a sun-like star

A University of Toronto team working from Gemini North in Mauna Kea, one of the twin telescopes at Gemini Observatory, has reported the first picture of a likely planet around a sun-like star. This has made headline science news around the world although the paper has not yet been published (a draft is available free online through the above link). The object has not yet been fully confirmed as planetary; it will take a while to confirm that it is moving through space with the star. --82.18.14.143 (talk) 18:01, 16 September 2008 (UTC)

Detection methods

All the methods stated in the article are well and good but there is an ommission. There's no mention of whether or not all of the methods have necessarily ever detected an exoplanet. Example: "Orbital phase: Like the phase of the Moon and Venus, extrasolar planets also have phases. Orbital phases depends on inclination of the orbit. By studying orbital phases scientists can calculate particle sizes in the atmospheres of planets." Is this last sentence valid? How many planets have been detected using this method overall? Pomona17 (talk) 15:06, 9 October 2008 (UTC)

Cleanup of "Discovery firsts"

I gave the "Discovery firsts" section a cleanup. To me, it seemed a bit dirty. I did not remove any designations that were previously there, I simply reworded some sentences. — NuclearVacuum 19:53, 16 October 2008 (UTC)

Eccentricity of Pluto's Orbit

This statement: "This is also an indication that our own Solar System may be unusual, since all of its planets except for Mercury do follow basically circular orbits.[3]" appears to assume that Pluto is not a planet. While I personally agree with this assessment I am not sure most people have demoted Pluto the a Kuiper Belt Object. —Preceding unsigned comment added by 71.135.110.11 (talk) 03:42, 3 November 2008 (UTC)

The relevant body (the IAU) defined "planet" in such a way that excluded Pluto back in 2006. This is not the right place to debate the merits of that particular decision. However, we should be reflecting that decision in the interests of accuracy. What "most people" think is nothing to do with it. CrispMuncher (talk) 22:41, 22 November 2008 (UTC)

List of Extrasolar Planets Images

I think we should make a new page showing all REAL pictures of Exoplanets, so that we can easily compare them and everything, I know there's not much pictures now, but I believe this will change in the nearby future! Leonlan (talk) 01:54, 23 November 2008 (UTC)

Removed questionable image

Pulsar PSR B1257+12 currently has three confirmed planets. But because they were discovered before the modern naming of extrasolar planets became common, the planets were named in order from the star and with uppercase letters.

I removed the image-and-caption to the right because (a) it's not labeled as an artist's conception; (b) I don't think the sizes of the planets relative to Earth are correct, based on the article text. Tempshill (talk) 05:51, 4 February 2009 (UTC)

Angular momentum

To my knowledge, the hypothesis that the F2 through K-type stars have lower angular momentum than O through F2 type stars because the angular momentum has been given to planets is not widely accepted. A more accepted current explanation is that the O, B, A rotate more quickly because they are younger, and haven't shed angular momentum. Therefore, I deleted the following text:

In careful spectroscopic observations it is found that rotational velocity drops off abruptly after spectral class F2 stars. It should be noted that the Sun is a G2 Class star (which is after F2.) Ninety eight percent of the angular momentum of the solar system derives from the orbital motions of the planets. In an isolated system, angular momentum must be conserved, so, of course, the remaining 2 percent lies with the sun. Therefore it seems that the angular momentum of the Sun has been transferred to the planets, that would otherwise cause the Sun to rotate 50 times faster than it currently does (approximately 2 km/s). If this hypothesis is correct, slowly rotating stars are so because a large portion of their angular momentum has been transferred elsewhere, perhaps to orbiting planets. Since ninety three percent of all main sequence stars are later than F2, it would seem that the bulk of stars in the galaxy may have planets, unless alternative methods of angular momentum transfer are proven likely.

If the deletion is incorrect, I'd like to see a citation. 128.156.10.80 (talk) 21:12, 9 February 2009 (UTC)

Eccentricity as selection effect?

The article states that the higher eccentricities of detected extrasolar planets as compared with Solar System bodies "is not an observational selection effect, since a planet can be detected about a star equally well regardless of the eccentricity of its orbit". Is that true? Don't both K and Pt increase with e? AldaronT/C 20:42, 30 July 2009 (UTC)

Yes, it's true that eccentricity is not an observational selection effect. I don't think that K and Pt depend on eccentricity. I knew that the higher orbital eccentricity have greater difference of orbital speeds between periastron and apastron distances. BlueEarth (talk | contribs) 21:20, 31 July 2009 (UTC)
But, for a given a and m, won't greater e bring the planet closer (at periastron) so that it exerts greater gravitational force (increasing K) and has a greater chance of passing in front of the star (for a given i, increasing Pt)? AldaronT/C 21:30, 31 July 2009 (UTC)
If the planet is more eccentric, the periastron distance is closer to the star than more circular orbit at a given semimajor axis. As the planet gets closer to the star, the semi-amplitude of the star and orbital speed of the planet will increase, and then decrease as the planet gets further away. I'll say that regardless of the eccentricity, the orbital period, orbital speed, and semi-amplitude are the same at a given semimajor axis and the mass of the star. Also I don't think that eccentricity of the orbit strongly affect the inclination, so it has no effect on the transit probability. But there is Kozai mechanism about how eccentricity affect the inclination of the orbit and their relationship. BlueEarth (talk | contribs) 22:15, 31 July 2009 (UTC)
Actually the detection efficiency for eccentric planets is slightly decreased, since the orbit is more difficult to sample. Think about it this way: the most significant change in RV occurs around perihelion, and for a very eccentric planet this occurs over a very short part of the orbit. For fixed planetary mass, this is mostly compensated by the increased K. At fixed K, the detection efficiency decreases above e ~ 0.6. See e.g. [7]. Just to clarify on a point made by BlueEarth - note that Kozai is to do with relative inclination to other objects in the system, the inclination parameter in exoplanet orbital elements is to do with the orientation of the orbit with respect to the line-of-sight. Icalanise (talk) 23:55, 31 July 2009 (UTC)
I see, so (looking at it the other way round) though K is increased, there's no selection effect, because the duration of the peak is shortened. Is the same true for Pt? AldaronT/C 01:19, 1 August 2009 (UTC)

(deindenting) Effect of eccentricity on transit probability also depends on the argument of periastron ω, which specifies how the orbit is oriented. Basically the transit probability depends on distance from the star. For ω close to 90 degrees, transit probability is boosted (and eclipse probability decreased), since the periastron occurs close to transit and apastron occurs close to eclipse. For ω close to 270 degrees, the situation is reversed: eclipse probability is boosted (and transit probability decreased). Icalanise (talk) 12:10, 1 August 2009 (UTC)

Extragalactic planet found

http://www.newscientist.com/article/dn17287-first-extragalactic-exoplanet-may-have-been-found.html Fences&Windows 22:10, 1 September 2009 (UTC)

Binary Star Systems

I am wondering if there has been any planets yet found orbiting binary or multiple stars? If this were the case would the systems be unstable through resonance effects if the the planet were massive enough and close enough to the stars?JeepAssembler (talk) 20:52, 18 September 2009 (UTC)JeepAssemblerJeepAssembler (talk) 20:52, 18 September 2009 (UTC)

Yes, there is a planet PSR B1620-26b which orbits the binary stars composing of a pulsar and a white dwarf. However, there are no known planets orbiting the binary or multiple stars composing of ordinary stars. I think that if planets orbit close to binary or multiple stars, their orbits would be unstable. Although if planets orbit binary or multiple stars far enough away, they would have stable orbits. I also think that the more massive planets would have greater resonance effects between the planets and stars, which make their orbits more unstable. BlueEarth (talk | contribs) 22:10, 18 September 2009 (UTC)
See also 55 Cancri. 55 Cancri A has five planets within 6 AU and a red-dwarf companion over 1,000 AU away. Astronaut (talk) 08:27, 16 November 2009 (UTC)

373-->403 19 oct 2009

Yippee! I got it first. Thanx to Sveriges Radio! ... said: Rursus (mbork³) 15:09, 19 October 2009 (UTC)

It finally passed the 400 milestone! Time to celebrate! :P —Terrence and Phillip 04:23, 25 October 2009 (UTC)

Do we really need the "Discovery firsts" section?

I know that this has been a perennial debate for this article, but it really seems to me that the "Discovery firsts" section is rather out of place. I would like to suggest that this article should be mainly about extrasolar planets in general, though it should certainly hit some highlights of individual planets. Detailed lists like in the "Discovery firsts" section seem more suited to an article like list of extrasolar planets. I won't move it myself for now, but I am interested in hearing others' thoughts on the subject. Kevin Nelson (talk) 10:13, 25 December 2009 (UTC)

As no one objected I have now indeed moved the section. Kevin Nelson (talk) 08:56, 9 January 2010 (UTC)
I wanted to read that section! Had it in my browser since before Christmas, came back and refreshed the page and it disappeared. I've added a "See also:" link at the top of the section. As you had it, the two articles had become almost completely disconnected. Also, where's the 1989 exoplanet on the discovery graph from? Can't see any mention of it in the article. 130.246.135.176 (talk) 22:00, 14 January 2010 (UTC)

Barycenter image

The image File:Planet reflex 200.gif

Planet reflex 200.gif

doesn't explain very much of anything except the difference between the solar system barycenter and the center of the solar system heaviest body, for which purpose it isn't used in this article. In order to describe radial velocity changes, the central star needs light waves emerging from the star, and a direction to the sun, which conventionally should be down in the image. A similar image describing transit method should have an image of the system seen from the side, so that the planet passes in front of the star, and a light curve is simutaneously running from left to right, like a light curve diagram from a variable star. Rursus dixit. (mbork3!) 12:02, 23 January 2010 (UTC)

Fourier Analysis

Has anyone ever tried to do a Fourier Analysis on observed exoplanets to see if their orbital periods could be broken down into components as a way to determine if there might be additional planets not yet discovered orbiting their star?JeepAssembler (talk) 21:37, 28 January 2010 (UTC)JeepAssemblerJeepAssembler (talk) 21:37, 28 January 2010 (UTC)

This may be a bit OT for the talk page, but the answer to your question is yes; looking at residuals on a periodogram is a pretty standard way of teasing out as much information from radial velocity data as possible. See, for example, the stuff on the "systemic" console here: [8]. J. Langton (talk) 01:23, 29 January 2010 (UTC)

Hatnote

The hatnote should not be there:

  • All these links are already used in ===Lists===
  • The hatnote is extraneous
  • see wp:hatnote

174.3.98.236 (talk) 15:24, 21 February 2010 (UTC)

Extrasolar planets and starspot cycles

I found an interesting paper about sunspots, which makes the interesting claim that tidal forces from planetary alignments might somehow have established the solar sunspot cycle. Now extrasolar planets are known which are very massive and close to the star. Is it possible to visualize starspots by looking at high-frequency light or the like, and see if they are driven by the orbit of those planets? Wnt (talk) 05:46, 3 March 2010 (UTC)

Mercury eccentric orbits

The article states that Mercury is the only planet in our solar system with an erratic orbit. I know that pluto is no longer condsidered a planet but none the less this statement seems somewhat misleading. Can someone with more experience than me clarify. Lonjers (talk) 21:54, 18 April 2010 (UTC)

There are eight planets in our solar system, seven have eccentricities less than 0.1, generally considering circular orbits, but Mercury orbits at an eccentricity of 0.2056, which is an eccentric orbit and the only planet in our solar system except for the former planet Pluto, which has an eccentricity of 0.2488. BlueEarth (talk | contribs) 19:30, 19 April 2010 (UTC)

The 40% figure

The article says that it is believed at least 40% of solar-type stars have low-mass planets. The source is a BBC webpage that quotes Stephane Udry. Udry is, of course, one of the most prominent astronomers in the field; still, I'm a little worried here because I haven't seen this number anywhere in the peer-reviewed literature and I'm really not sure how Udry came up with it. In fact, the number seems a little on the high side to me--might only high-metallicity stars count as "solar-type" here? Anyway, I'm not going to delete the statement from the article, but if anyone has any more information about this it would be useful. Kevin Nelson (talk) 07:14, 22 April 2010 (UTC)

Sentence about lack of water

I recently deleted a sentence that mentioned several exoplanets were found to lack water. Quantanew restored the sentence and provided a source for it (Scientific American, Feb. 2007). According to that article, water was found to be absent in the atmospheres of HD 189733b and HD 209458b. Though I would consider that to be a reputable source, it is now outdated. Water has now been found in the atmospheres of both planets, as indicated by the following two sources: Grillmair et. al. (Nature 456:767, Dec. 2008) and Swain et. al. ( Astroph.J. 704:1616, Oct. 2009). Though not everyone will be able to access the full articles at those URLs, the abstracts give the essence of the information.

Accordingly, I am deleting the sentence again. Of course, if anyone wants to discuss the issue further I will be happy to do so. Kevin Nelson (talk) 21:38, 25 April 2010 (UTC)

Yeah I wasn't aware of the paper on HD 209458b you are correct Quantanew (talk) 05:20, 26 April 2010 (UTC)

Excising the pulsar planets from history?

I do like the way that the pulsar planets, despite constituting the first confirmed extrasolar planets (also, first confirmed "super-Earths", although the term wasn't coined until much later) are left out of the list of notable extrasolar planets. It's also enlightening to read that Gliese 581 e is the lightest exoplanet currently known, this claim seems somewhat dubious in the light of PSR B1257+12A. 86.148.145.35 (talk) 22:42, 27 December 2009 (UTC)

I have no horse in this race, but it's worth noting that this bias reflects a bias in the literature. See for example the official announcements of HD 156668 b which call it the "the second smallest exoplanet ever discovered", even though it's more massive than the brown dwarf companion MOA-2007-BLG-192-L b, and the pulsar planets PSR B1257+12A, B, and C. It's also worth noting that there is a rationale to this bias: pulsar planets, for example, are probably small for reasons that have little to do with the reasons that excite interest in small planets orbiting normal stars. AldaronT/C 04:23, 8 January 2010 (UTC)
What the first commenter refers to is not "bias". Yes, there is less research being done on the pulsar planets, and therefore less published material about them; that is bias, and indeed it is reasonable. But both in the popular press and even in many refereed papers, there is a tendency to describe 51 Peg as the "first confirmed exoplanet", or Upsilon Andromedae as the "first multi-planet system". This is not bias; it is factual error. While they may not be of interest to all exoplanet researchers, the PSR B1257+12 planets are nevertheless the first confirmed discovery, the first multi-planet system detection, and — for now at least — include the smallest detected exoplanet. Ignoring these and other such facts, or dismissing them as insignificant, is a disservice to everyone. 75.161.106.136 (talk) 00:09, 28 April 2010 (UTC)
Those are good intentions; but whether you call it "bias" or "factual error", it's present in the literature, so it has (unfortunalty) to be repeated here. Wikipedia has strict policies about original research, even where it corrects errors or biases that the editors can see. AldaronT/C 04:15, 28 April 2010 (UTC)
It doesn't have to be repeated here as fact however. It is not original research to point out that something discovered in 1992 was discovered before something discovered in 1995: this is obvious and trivial. Same goes for a 2 lunar mass planet being less massive than a 2 Earth mass one. The honest course of action is to state that these claims are often made (with sources to back this up) but that they are incorrect (again with sources to back it up). Icalanise (talk) 20:55, 28 April 2010 (UTC)
Yes, I agree, which is why I have no problem with the specific recent edits by 75.161.106.136. My point is in response to the general desire to repair a real bias in the literature, or to edit or "fix" statements that pretty much repeat exactly what's said there, just because we "know" it's misleading. Of course, if there are sources, then the problem is gone. AldaronT/C 21:42, 28 April 2010 (UTC)

Argument of periastron

Why does argument of periastron use negative values for some planets as listed in EPE. For example, the argument of periastron of −70° is identical to 290°. 180° and −180° are identical. 0°, −0°, 360°, and −360° are identical. BlueEarth (talk | contribs) 21:17, 28 April 2010 (UTC)

Orbital revolutions

I think that about half of all extrasolar planets orbit the stars in a clockwise path, unlike in our solar system which all eight planet orbit our sun in a counterclockwise path. Do you think so? BlueEarth (talk | contribs) 21:17, 28 April 2010 (UTC)

This kind of speculation isn't really appropriate here - talk pages are for discussion of the article. Icalanise (talk) 21:25, 28 April 2010 (UTC)

Merger proposal for Sudarsky extrasolar planet classification

The article Sudarsky extrasolar planet classification describes an obsolete and unused system of exoplanet classification at great length, without context and without reference to the difficulties associated with obtaining information about almost all of the attributes on which that system is based. At best, the Sudarsky system should be considered "hypothetical" and discussed critically, in the context of an up-to-date review of detection methods and other systems of classification here. AldaronT/C 21:35, 20 March 2010 (UTC)

  • I would suggest to keep that article unmerged. I think that in 2015 IAU assembly, it may turn obsolete Sudarsky classification into a very useful classification. That article is interesting to me that it talks about what gas giants are like if they orbit lot closer to stars than Jupiter and Saturn. But sooner or later, transits will enable astronomers to study a variety of gas giants. Although the lowest class giant planet found by transit is clarified jovian, water jovians may be detected by transit very soon!! If astronomers manage to study the atmospheres of hot Jupiters, clarified jovians, and water jovians by transit, it may revolutionize the knowledge about how giant exoplanets may look like, what clouds are made of, and what atmospheric dynamics would be like for those planets not found in our solar system. The planet COROT-9b is probably a clarified jovian since this planet orbits at 0.407 AU and its temperature likely to be more than 350 K despite given it between 250 to 430 K. Future transit observations of this planet will study the chemical makeup of the atmosphere and whether or not have clouds. BlueEarth (talk | contribs) 23:46, 20 March 2010 (UTC)
  • I agree with the idea to delete or merge the Sudarsky planet classification article - the article is far too large at present, giving undue weight to one form of classification system which is largely unconstrained by observations. Furthermore, in the domain where it can be tested against reality (i.e. hot Jupiters), it doesn't seem to work very well. Icalanise (talk) 10:37, 3 April 2010 (UTC)
I also agree with the proposal. User:BlueEarth may be right that the Sudarsky classification system will become useful in the future, but at present it does not seem very notable. I just haven't run across many mentions of it in the astronomical literature. Having a few sentences about it does seem reasonable, and those can be added to this article. Kevin Nelson (talk) 23:41, 12 April 2010 (UTC)

Oppose merger. The second paper has been highly cited. Qurq (talk) 14:05, 15 April 2010 (UTC)

The paper is cited, but is the classification scheme? I'd reconsider if I could find examples where that was the case, but the fact that (as near as I've been able to tell) the paper is often cited, but the scheme is never cited, just supports the argument that the scheme is obsolete and unused. AldaronT/C 18:31, 15 April 2010 (UTC)
Well, I was with you until just a few days ago when I did in fact run across a citation of the classification system. Deeg, et al in Nature: http://www.nature.com/nature/journal/v464/n7287/full/nature08856.html . I'm still not terribly enthusiastic about the article on the system, since as a general rule I don't like Wikipedia articles whose sole purpose seems to be to summarize a single scientific paper. But I'm a little more favorable to it now. One idea is that we could add a whole new section to this article about modelling of the structure of exoplanets, and that could be a subsection within it. Kevin Nelson (talk) 07:20, 22 April 2010 (UTC)
Any more discussion of this subject? As I understand the policy, a consensus is needed in order for the proposal to be adopted, and so far it looks to me like there is no consensus either one way or the other. Kevin Nelson (talk) 10:09, 2 May 2010 (UTC)
I read about 10 peer reviewed articles on (transiting) exoplanetology a day, I don't consider myself an expert, although it is my field of research and I've never even heard of Sudarsky - maybe I'm just ignorant ?? ..but I oppose merger. User:Gmoney484 (talk) 8:32 25 May 2010 (UTC)
The authors of the COROT-9b discovery paper (Deeg et al.) refer directly to the classification system of Sudarsky et al. -- oppose merger. Orb85750 (talk) 15:25 26 May 2010 (UTC)

It might be better to merge into gas giant instead of this article anyway. Icalanise (talk) 19:29, 6 May 2010 (UTC)

Sounds plausible to me. Anyway, I will remove the note about the proposal from the top of the article. Kevin Nelson (talk) 09:26, 9 May 2010 (UTC)
I see that the note is still there at the top of the article Orb85750 (talk) 12:16 27 May 2010 (UTC)

Does the "News" subsection really need to be there?

In the "External Links" section, there's a "News" subsection that I'm inclined to get rid of. I mean, it's not terrible---there are some good links in it. But all in all, it seems like a pretty miscellaneous bunch. A lot of the sources it links to are now pretty out of date, and the principle for inclusion is extremely unclear. Really, it seems to me that any source here that gives important information can be referenced or mentioned elsewhere. I won't delete it until I wait to hear what other people have to say about this. Kevin Nelson (talk) 09:52, 9 May 2010 (UTC)

Not sure where this would go

Recently there was an article published on 2:1 resonances may hide planets. I think I could type it up myself... I don't know, cause I just can't find anywhere to put it. Syntheticalconnections (talk) 17:08, 9 May 2010 (UTC)

Well, I placed it in the article under "Other Mysteries" which I just created. I am not sure if it should be moved. Syntheticalconnections (talk) 17:20, 9 May 2010 (UTC)

Designation by orbital period

There are now many systems where the designations do not follow the orbital periods, yet there is still no transition to the orbital period designation system. I suspect the statement that this system may become useful in the future is verging on WP:CRYSTAL. Icalanise (talk) 18:06, 3 June 2010 (UTC)

Agreed. Removed. AldaronT/C 18:31, 3 June 2010 (UTC)

You'd see that there was a cited reference for that, about designations by orbital periods but didn't say that this designation will become useful in the future. BlueEarth (talk | contribs) 22:07, 3 June 2010 (UTC)

1RXS_J160929.1−210524

Might want to update this article with picture and information about 1st visible exoplanet, Sadads (talk) 11:45, 8 July 2010 (UTC)

The title of "First" is dubious.
Not only was Fomalhaut b confirmed as a planet a couple of years ago, but the first pictures of Fomalhaut b were taken in 2004. What can be said is that the image of 1RXS was *published* before that of Fomalhaut b. But none of that matters because a picture of the planet Beta Pictoris b was taken in 2003 and recently confirmed as a planet, so this beats both 1RXS and Fomalhaut b as the first image of a confimed extrasolar planet.
Qurq (talk) 11:09, 9 July 2010 (UTC)

Extrasolar Planets Encyclopaedia or JPL's Planetquest?

Which number should be used? As of this morning Extrasolar Planets Encyclopaedia has 473 as the figure, JPL's Planetquest website has 463 as the figure. Why the discrepancy? Which number should be used in the article?--RadioFan (talk) 12:07, 16 August 2010 (UTC)

We use number from EPE because this site keep track on new planets better than PlanetQuest. BlueEarth (talk | contribs) 20:07, 16 August 2010 (UTC)
Can you expand on that? HOW does it keep better track? More up to date? Uses different criteria?--RadioFan (talk) 14:05, 17 August 2010 (UTC)
The reason why EPE better track on new planets discovered is that because EPE is updated almost every day, but PlanetQuest does not. So EPE is more up-to-date than PlanetQuest. The different criteria for EPE is to have a lot of articles listed in bibliography about the discoveries, observations and modelling of the exoplanets while PlanetQuest list few article about the big discoveries and new observations. The similar criteria is the list of the latest news, table of exoplanets, and pages about the specific exoplanets. BlueEarth (talk | contribs) 21:00, 17 August 2010 (UTC)
I dont understand what you mean by "The different criteria for EPE is to have a lot of articles listed in bibliography about the discoveries" The articles provide good references but I dont think that's different criteria. Is there different criteria for inclusion on EPE vs. PlanetQuest? Does PlanetQuest include only peer reviewed discoveries while EPE includes any reported finding (just an example, I dont know, thats why I'm asking). We've put a lot of faith in EPE here and I'd like to understand why.--RadioFan (talk) 23:26, 24 August 2010 (UTC)
Might be worth taking a look at what the EPE gives as its inclusion criteria: these are listed here. Icalanise (talk) 16:13, 11 September 2010 (UTC)

Notable discoveries of extrasolar planets

I just removed this section from the article. The article on extrasolar planets should provide a general overview of the concept of an extrasolar planet, not be a listing of every new discovery of one. While the information I removed is partially already in List of extrasolar planets, perhaps it could be spun off into a new article, Discoveries of extrasolar planets. Thoughts? NW (Talk) 15:09, 25 August 2010 (UTC)

I agree with you, we should cut-and-paste all that discovery info to Discoveries of extrasolar planets. In the extrasolar planets article with all that discovery info, browsers would take longer to load this page than this article without discovery section. BlueEarth (talk | contribs) 21:21, 25 August 2010 (UTC)

Kepler-9

The NASA web site list 2 or 3 new planets around Kepler-9. May need to update the list and counts 76.115.122.200 (talk) 23:19, 26 August 2010 (UTC) Norm Jette

"Exact" planet count

Now we have nearly 500, can we stop giving an "exact" updated count. Sometimes this figure goes down because discoveries are retracted or disputed like with Gliese 581g. The number is taken from The Extrasolar Planets Encyclopaedia but that website is sometimes not updated for hours or days after a new planet is announced, so the figure isn't really exact. There are also hundreds of candidates awaiting to be confirmed, so an exact figure isn't very meaningful anyway. I've edited the article to say "nearly 500". 89.241.238.127 (talk) 18:47, 14 October 2010 (UTC)

We use The Extrasolar Planets Encyclopaedia because is the best available reference, see the discussion above Extrasolar Planets Encyclopaedia or JPL's Planetquest? and yeah some discoveries are retracted or disputed but still EPE keep tracks of the changes and the planets candidates are by name candidates awaiting to be confirmed, for example HATNet has found ~1200 transiting planet candidates. About 1 in 20 candidates survives see Bakos et al. I believe the number of planets is very meaningful, so we definitely should count them for scientific and encyclopedic reasons.Quantanew (talk) 19:14, 21 October 2010 (UTC)
I'm not disputing linking to it as the best catalog. I'm disputing quoting an "exact" number. Some days ago it was 496. Then it went down to 494. It has since gone down again to 493. Soon it will go up again, and I'm sure it will continue to fluctuate. A number that goes up and down like this cannot be said to describe an "exact" number of planets. Besides we know there are bilions of planets, so this number is a track of the size of the catalog and we only really need an approximate size. At some point in the next couple of years this article will probably say "over 1000 such planets" with a link to the catalog for further details, and that will be good enough. I think the real issue is that people want the fun of continually updating the count (up or down). 2.97.18.38 (talk) 20:28, 21 October 2010 (UTC)

See also this email from The Extrasolar Planets Encyclopaedia mailing list:

[Exoplanets] Warning about the coming detection of "THE" 500th explanet,  Schneider Jean

          o From: "Schneider Jean" <jean.schneider@obspm.fr>
          o To: exoplanets@obs.ujf-grenoble.fr
          o Subject: [Exoplanets] Warning about the coming detection of "THE" 500th explanet
          o Date: Sat, 16 Oct 2010 10:37:39 +0200 (CEST)
          o Importance: Normal


This message is a warning for those who would be tempted to celebrate
the detection of "THE" 500th exoplanet.

The number of exoplanets, recored for instance at http://exoplanet.eu ;,
is necessarily subject to some uncertainty for several reasons:
- the mass limit below which a substellar object is called a planet
  is somewhat arbitrary
- the mass measurement is always affected by some instrumental inaccuracy
- whatever this mass limit is, the true mass for most planets is subject
  to some uncertainty, intrinsic to the detection method (unkown
  inclination of the orbit, modelisation of planet atmosphere)
- some planet detections, even published in refereed papers, are sometimes
  retracted afterwards

For all these reasons
1/ The boundary between "confirmed"/"unconfirmed" planets is somewhat fuzzy
2/ The number of planet candidates at http://exoplanet.eu ;(collected
   in the survey of professional litterature, conferences or websites)
   is affected by an uncertainty of a few units.

Jean Schneider
Pris Observatory

ps I am grateful to those who point out errors in the catalog at
   http://exoplanet.eu

Taken from http://tamise.ujf-grenoble.fr/wws/arc/exoplanets/2010-10/msg00001.html 2.97.20.98 (talk) 17:28, 27 November 2010 (UTC)

Clicking on that link takes you to a page which asks you to click a button to confirm you are not a spambot or something, then there is a grid of numbers, click on the number 10 in the row 2010, then two emails will be listed, click on the one that says "# [Exoplanets] Warning about the coming detection of "THE" 500th explanet, Schneider Jean" 2.97.19.188 (talk) 23:59, 27 November 2010 (UTC)

I appreciate the concerns about implying a definite number, and to my mind the current sentence could be reworded to point out these are the planets listed in a reliable catalogue, not all those claimed/verified by astronomers. However I somewhat like the fact people are eager to update the number, it keeps this article active and may encourage such an editor to improve other areas. ChiZeroOne (talk) 00:20, 28 November 2010 (UTC)
Fair enough. A discussion about how many numbers we can expect in the coming years appears in http://www.scientificamerican.com/article.cfm?id=exoplanet-catalogue 2.97.17.37 (talk) 20:35, 29 November 2010 (UTC)

Confirmed discoveries

The existing article quite rightly lists the Gamma Cephei system (1988) as the first confirmed exoplanetary system. However, the validity of that system was disputed for several years before being ultimately confirmed, and in fact the original discovery claim was retracted for several years due to insufficiently high quality data. I would suggest adding a few sentences about the second confirmed exoplanetary system, HD 114762 (1989), which was never disputed to exist. The issue was whether the detected companion, at 11 Jupiter masses, was a planet or a brown dwarf. By current standards, the object falls firmly in the planet side of the divide, so this system counts as the second confirmed, and first undisputed confirmed, exoplanetary system. —Preceding unsigned comment added by 99.243.61.181 (talk) 02:54, 13 December 2010 (UTC)

Category:Extrasolar planets removed

What's the justification for removing this article from Category:Extrasolar planets? World War II, for example, is in Category:World War II. Rwessel (talk) 08:07, 27 February 2011 (UTC)

Just because something is done elsewhere on Wikipedia doesn't mean it is the right thing to do. Personally I agree with the removal, the category page Category:Extrasolar planets already links to this article at the top, there is simply no need for duplication. Moreover, as supported by how the category is currently used, the implication of the category is that it contains articles on the actual extrasolar planets themselves (or lists of them) rather than the concepts behind them. If anything the generic exoplanet article is more appropriate under something like Category:Exoplanetology but even then it is already referenced. ChiZeroOne (talk) 17:27, 27 February 2011 (UTC)

Image by Lucianomendez in Extrasolar planet#Unanswered questions

Planeta extrasolar y satelite similar a la tierra.jpg

I've reverted the artistic image (right) of an Earth-like moon orbiting a gas giant (apparently an original work by Lucianomendez) a couple of times, and it's gotten put back, now with the caption explicitly identifying it as an artist's impression.

My impression is that since the image is completely speculative, it's not really adding anything to the article, although as currently captioned, it's not particularly harmful. Frankly I'm not sure exactly how {WP:OI} applies here. So rather than just reverting again, I thought we’d discuss... Rwessel (talk) 03:32, 9 February 2011 (UTC)

The image is watermarked anyway which is against image policy, I will remove as a result since it's advertising a private blog. Apart from that I agree it's not particularly educational and entirely speculative. ChiZeroOne (talk) 03:52, 9 February 2011 (UTC)

And it's back... (sans watermark.) Rwessel (talk) 02:16, 11 February 2011 (UTC)

I think the issue here is whether or not to include a space art image. Space art is realistic art based on knowledge of outer space, and illustrates objects and places that hasn`t been imaged yet. Space art is widely accepted and used in science publications in different media, and it has didactic purposes. I don`t know exactly why space art doesn`t applies here. Lucianomendez (talk)

It's not that space art is inappropriate, it's that this particular piece of art does not illustrate anything better than the accompanying words. For example, Haumea has art that illustrates its shape, colour, and size relative to its satellites; it helps to visualise something that is difficult to describe, and it uses the actual data of a specific object. The art here, however, adds nothing to the words, in either content or clarity. Also, it isn't even of "objects and places that hasn't been imaged yet", it's completely imaginary. It's okay for a glossy magazine on a news-stand, but I don't think it belongs here. Tbayboy (talk) 21:19, 12 February 2011 (UTC)

I agree with Tbayboy: now the image refers to a specific object, Upsilon Andromedae d, an example of a planet that lies in the habitable zone. If it has large moons they may be able to support liquid water. The image is based on information taken from Sudarsky extrasolar planet classification, like the appearance of a class II gas giant with with water vapor clouds instead of the yellow-reddish clouds that had the previous version of this image, caracteristic of colder planets like Jupiter. Lucianomendez (talk) 21:20, 13 February 2011 (UTC)).

I agree with Rwessel and Tbayboy. It's entirely speculative and should not be here. I'd go so far as to say it conveys false information by rendering moons that are not known to exist. I think this type of art conveys misleading information about what is known. 66.27.66.8 (talk) 17:57, 4 June 2011 (UTC)

I also agree with Rwessel and Tbayboy and the anon in that this particular image does not help illustrate known information, in particular that it misleads by showing speculative moons. However, I would accept a variation that did show something informative, such as the relative sizes of the detected Ups And exoplanets (as far as the scientists are able to determine), or even one showing the orbits with exaggerated planet sizes. (I have taken the liberty of correcting the user talk link two posts up) -84user (talk) 21:48, 4 June 2011 (UTC)

Outdated image?

The image on this article seems to be outdated. According to charts and many different articles, planets such as SWEEPS-10, OGLE-2005-BLG-390Lb, and MOA-2007-BLG-400Lb are much further than 300 light-years. The image does say “most”, but I am sure there are plenty more than the three I listed. Should there be a more updated image or is this one still sufficient? Thoughts? A. Z. Colvin • Talk 00:51, 5 March 2011 (UTC)

There are now well over 500 known exoplanets, you are going to have to find quite a few more examples before "most" no longer applies, ~250 more. It is not outdated, it is perfectly correct so far, though the net is gradually expanding. It's not an accident that two of the three planets you mention have been found via microlensing. Often the planets "found" using this method are more distant. However microlensing planets make up a tiny fraction of all the exoplanets discovered so far (see the List of planetary systems graph), the vast majority having been discovered by Radial Velocity (where it helps if the star is closer). ChiZeroOne (talk) 02:17, 5 March 2011 (UTC)
I thought of that after I posted this lol. I guess after the Kepler findings are confirmed, the image may be outdated. Thanks. A. Z. Colvin • Talk 06:01, 7 March 2011 (UTC)

the NEVER announced extrasolar planets by extrasolar planet encyclopaedia since august of 2009

i was check the extrasolar planet encyclopaedia (EPE) ,and there is 5 extrasolar planet that NEVER been announced…

this the scientific paper of 08/2009: http://exoplanets.org/papers/sixpack.pdf

and this is extrasolar planet catalog in alphabetic order: http://exoplanet.eu/catalog-all.php?&munit=&runit=&punit=&mode=1&more=

i send a e-mail for EPE, but they just told that the authors of this paper,don’t give the EPE the right of publicate this paper on the EPE

this is strange because this planets it’s not secret, it’s already been announced since august of 2009 on the California Planet Search http://exoplanets.org/papersframe.html

i don’t know, but for me, look like if something like that start happen in the EPE, that is the great reference in extrasolar planet of all.Now they could lose the credit of announce new exoplanets

now because of this it's supposed to have 429 planet and not 424,anyone know why,this planets it's not on EPE catalog?

the unannounced planet are: HD34445b, HD126614b, HD24496b, HD13931b, Gl179b

there is one small note on the discussion on the end of this paper that talk about of the unannounced planetary system of Gl 179 a M dwarf star ,on a recently announced planet around HIP 79431 another M dwarf star with a gas giant planet see at:

http://arxiv.org/PS_cache/arxiv/pdf/1001/1001.1174v1.pdf

HD34445b, HD126614b, HD13931b and Gl179b are on the EPE and there are Wikipedia articles about them. There is also a Wikipedia article about HD24496b, which is indeed not on the EPE (even in the unconfirmed, controversial or retracted section). However, the article has no refs; the scientific paper referred to does not mention a planet of that name (it talks of four planets); I can find no trace of any such planet on any other of the well-known exoplanet databases; and Google only produces results seemingly based on the Wikipedia article. Not very strong grounds for altering the 'total' number; indeed stronger grounds for deleting the Wikipedia article! Cuddlyopedia (talk) 13:57, 29 September 2011 (UTC)

Wikipedia:Articles for deletion/Aldebaran in fiction

Also nominated Fomalhaut, Alpha Centauri, Sirius, Epsilon Eridani and several others. All opinions welcome. Thank you. walk victor falk talk 13:01, 15 April 2011 (UTC)

"Image gallery" in lead

I figured I'd begin a discussion, since a tag was thrown on with only the edit description "Too many images in lead, adding tag." Would a mosaic of these images, or more preferable ones, be in favor? —Onore Baka Sama(speak | stalk) 14:43, 8 May 2011 (UTC)

I would agree with that editor that currently the lead does seem a bit cluttered with images. A mosaic might be a solution, the only problem I think there could be with that is that in losing the lengthy captions just what the images are showing may be lost on those unfamiliar with the subject. ChiZeroOne (talk) 15:28, 8 May 2011 (UTC)
There are too many images in the lead section. Reducing it down to one or two, like just using the image of AB Pictoris.Piper2000ca (talk) 11:58, 9 May 2011 (UTC)
I like the images. I wouldn't call it an image gallery, but maybe they could be better distributed throughout the article. GreenPine (talk) 19:21, 19 May 2011 (UTC)
I think the images are fine. Five lead images hardly constitutes a gallery and they are representative. As the AB Pictoris companion may be a brown dwarf it may not be as relevant so could be moved to the section Confirmed discoveries where brown dwarfs are discussed.66.27.66.8 (talk) 18:08, 4 June 2011 (UTC)
Also, one or two of the images whose captions indicate uncertaintity could be moved to the "Definition" section and usefully reworded. For example, the GJ 758 image's caption ends with "It is unclear whether the companions should be regarded as planets or brown dwarfs" and the AB Pictoris image has "Coronagraphic image of AB Pictoris showing a companion (bottom left), which is either a brown dwarf or a massive planet." -84user (talk) 21:59, 4 June 2011 (UTC)

Outdated image

The Image: Exoplanet Period-Mass Scatter.png is more than 1 year old. Yould be nice to update it. At least 200 more exoplanets have been found since then. — Preceding unsigned comment added by 217.91.113.209 (talk) 13:17, 17 October 2011 (UTC) --217.91.113.209 (talk) 14:53, 17 October 2011 (UTC) ThomasH

Giordano Bruno section inaccurate

So, I've twice updated the section on Giordano Bruno, and it's been twice reverted. The article currently states that Giordano Bruno was burned at the stake for his belief in the plurality of worlds, but this is inaccurate, as I have proven with two different valid sources (the Stanford Encyclopedia of Philosophy and the Catholic Encyclopedia). These sources disagree with the New Encyclopedia Britannica, currently cited in the article, but they are in agreement with Wikipedia's own article on Bruno, which provides no citations to support the viewpoint that he was executed for his astonomy (but provides several citations to prove the contrary). What gives? When two sources disagree, is it Wikipedia's policy to automatically favor the one that's more hostile to religion?

And shall I expect to soon see Bruno's article "amended" to reflect the party line here? — Preceding unsigned comment added by 75.166.32.178 (talk) 17:48, 25 November 2011 (UTC)

I haven't looked yet through Giordano Bruno, but a general answer is (i) wikipedia articles themselves can not be used as references or reliable sources; (ii) Britannica is considered much more reliable than Encyclopedia of Philosophy and the Catholic Encyclopedia (I'm not sure the last two are WP:RS). Any chance for a proper reference (e.g. a book written by a historian and/or published by a major publisher)? Materialscientist (talk) 23:11, 25 November 2011 (UTC)
I've looked through reverts. This might be reliable, this probably not (for an WP:FA). Other opinions are welcome. Materialscientist (talk) 23:19, 25 November 2011 (UTC)
I agree with 75.166.32.178 that there was an inaccuracy, or at least a potentially misleading statement, about Giordano Bruno. On the other hand, a very brief mention of Giordano Bruno seems to be all that is called for in this article. I have tried to do another rewrite that will serve temporarily, though I'm sure it can be improved further. I would definitely consider the Stanford Encyclopedia of Philosophy to be a reliable source and so I have left in the citation of its Copernicus article. Also, I would like to remind everyone to assume good faith (WP:AGF). Many different people have worked on this article, and there is no "party line." Kevin Nelson (talk) 01:59, 26 November 2011 (UTC)

Trimming of section about proposal of Hessman et. al.

I am planning to do some major trimming of the section that discusses the proposals of Hessman et.al. Personally I think those proposals have merit, but right now it looks to me like the article gives excessive attention to a three-page open letter on Arxiv that apparently has never passed peer review or been published anywhere. Kevin Nelson (talk) 04:57, 30 November 2011 (UTC)

Concepts can be more clearly and cleanly presented

Star
Constellation
Right
ascension

Declination
Apparent
magnitude

Distance (ly)
Spectral
type

Mass
(M)
Temperature (K)
Age
(Gyr)
Confirmed
(unconfirmed)
planets
Notes
unknown unknown unknown unknown unknown unknown unknown unknown unknown unknown unknown -
unknown unknown unknown unknown unknown unknown unknown unknown 1656 unknown unknown -

I am in the process of the transformation of Extrasolar planet lists such as List of extrasolar planets detected by radial velocity. As you can see with the links above I am unable to link to this article as the concepts aren't necessarily explained well enough here. The problem is I want to ideally avoid sending the reader into reading tens of multiple paged articles just to make sense of the lists. Any suggestions? -- A Certain White Cat chi? 04:59, 29 January 2012 (UTC)

Hmm, that seems like a rather difficult problem. The thing is, there are a lot of different kinds of concepts here--some are qualitative, some are quantitative, etc. Several of them could certainly have wikilinks to the Orbital elements article, so maybe that will help a little. Kevin Nelson (talk) 13:13, 2 February 2012 (UTC)

Math doesn't work

According to the intro,

A total of 777 such planets (in 623 planetary systems and 105 multiple planetary systems) have been identified as of July 5, 2012.[1]

This cannot be true. Since each multiple planetary system has at least two planets, the number of exoplanets discovered must be at least 833 (= 623 + 105 x 2). Also, the data is current as of July 5, 2012, but the source is 2011.24.69.174.26 (talk) 17:35, 13 July 2012 (UTC)

Ah, the 623 figure includes both single and multiple planet systems. I'll edit the article to make this clear(er).24.69.174.26 (talk) 17:46, 13 July 2012 (UTC)

add Exrasolar climate here?

108.195.138.247 (talk) 04:00, 14 August 2012 (UTC)

new method: eclipse timing?

as used in the polish project Solaris, with 3 telescopes in the southern hemisphere. is this a new method of detection?--78.53.64.246 (talk) 15:04, 13 September 2012 (UTC)

This method is already mentioned in the methods of detecting extrasolar planets article, though curiously in a separate section and with an odd title of "eclipsing binary minima timing". In scientific literature this tends to be called the ETV, or Eclipse Timing Variation method, and as the name suggests it is really just a subset of the Transit Timing Variation method, both being extensions of the Transit method in general. Really, discussion of all these should be combined. ChiZeroOne (talk) 15:43, 13 September 2012 (UTC)

Warning: reference 83 is total bullshit

Hallo,

I've studied reference 83 ( http://www.cosmosmagazine.com/node/1658 ) a lot, and found, that it is nearly total bullshit. I suppose switch to another reference, probably from a scientific source, and not from a dilettant webportal.

××××

The section has been rewritten and new references have been added. Qurq (talk) 17:49, 29 August 2012 (UTC)
This is a troll, who expectably has not signed his name in order to evade any threats to his reputation. There was no need to rewrite the section at all, and the source is reliable. I've seen this kind of trolling ("this is not scientific" trolling) in the past. Wer900talk 20:19, 4 January 2013 (UTC)

Get ready ;)

NASA Kepler hints at over 250 new potentially habitable worlds

--Exsaol (talk) 20:06, 4 January 2013 (UTC)

Exciting news, indeed. I read the PHL press release, and it's fascinating stuff. How should we integrate it into the article, though? Wer900talk 20:14, 4 January 2013 (UTC)
There should be some more official stuff from Kepler folks at the AAS meeting in couple of days(I think next Tuesday they have their presentation)

--Exsaol (talk) 21:24, 4 January 2013 (UTC)

I added the most recent information from the HEC into the habitability section. I hope that the AAS meeting yields more for us! Wer900talk 22:36, 4 January 2013 (UTC)
So far they revealed 4 new habitable candidates, with one orbiting Sol-type star in 240 days and with radius of 1,5e. Of course this is very subjective, geology and other factors that we can't yet determine might influence it.

--Exsaol (talk) 22:00, 7 January 2013 (UTC)

A planetary system is not a solar system

A solar system is not a planetary system; it is the system consisting of a sun and all bodies that revolve around it. This includes planets, moons, asteroids, comets, dwarf planets, and in our case at least, Kuiper objects and the Oort cloud.

Would you call Jupiter and its moons a moon system, or a lunar system?

The term "solar system" has two meanings: Our solar system, and similar systems elsewhere. Stars are sometimes referred to as "suns". So why not the same for "solar systems"?

Even if one insists on not calling other solar systems solar systems, a solar system and a planetary system are not the same thing. The latter is a subset of the former. Calling it a star system is even worse, as that would be a system of stars, not a solar system.

One often hears "our solar system". One also hears "our galaxy". But no one says "our Milky Way". Hence the "Milky Way" refers only to our galaxy, "galaxy" refers to any galaxy, and "solar system" can be ours or another similar system.

From webster.com:

solar system noun Definition of SOLAR SYSTEM

the sun together with the group of celestial bodies that are held by its attraction and revolve around it; also : a similar system centered on another star

The term "planetary system" excludes the star about which its constituents orbit, and is therefore not a solar system.

Betaneptune (talk) 20:44, 9 February 2013 (UTC)

What if all of these discoveries of extrasolar planets it's just mistake?

The recent discoveries of extrasolar planets remind me the Niagri waterfall.Exept one, All of these discoveries have no solid base. Because all these these phantom meant to be as discovered planets have unnatural for normal planets orbital period of rotation .I'm no argue, a telescope, "Kepler" have a high-quality optical system, which allows us to see the change in brightness of distant "sun" because of that "sun" also has spots on its their surface too. But I try to explain, the shine of our Sun also changes because of the number of sunspots on it's surface is chenges too . Glize 581, an old worn-out star and spots on its surface will be very much. Not the movement of planets around the star sees "Kepler" but the period of axial rotation of it star around itself the "Kepler" sees . We almost unknown nature of the stars, all that we have - the spectrum and hypothesis .I based on simple and obvious conclusion then more star darker than the darker spots on its surface, all the stars has the spots this is axiom. In general, the transit method is very doubtful .It's not enough time for the observation for the "Kepler" and for observers to make right conclusion. Petrov Vlad — Preceding unsigned comment added by Petrov Vlad (talkcontribs) 21:25, 19 March 2013 (UTC)

Well Kepler has a lot of clearing mechanics for false signals, like the need for 3 events to be recorded to recognize as a KOI (kepler object of interest) what are the statical odds of sun spots occurring a same time in same place 3 times? also all the others tests (algorithms, RV, TTV, dynamical simulations, etc) Quantanew (talk) 15:03, 20 March 2013 (UTC)
Quantanew is right. There are numerous clearing mechanisms for ensuring that planets are indeed actual planets, and this involves several tests such as a high signal-to-noise ratio, recurrence of the signal at least three times, confirmation that there were no eclipsing binaries creating the signal, and many others. Kepler has observed only a few tens of thousands of thrice-recurring threshold crossing events, and some which have passed additional tests (~2,000) are known as planet candidates. Only 114 planets have been conclusively identified by the Kepler team, constituting buy 0.7% of all detections with a chance (and an even smaller proportion of all detections) of being actual planets. Therefore, I think that given all of the tests that are conducted, all of Kepler's planets detected to date do exist (Don't get me wrong, planets can be "un-confirmed" and have been in the past, but this is getting less common as we deploy better equipment and statistical methods). Wer900talk 20:35, 23 March 2013 (UTC)

Nomenclature section

Two things:

I suggest switching the third and fourth paragraphs in the subsection "Extrasolar planet standard" of "Nomenclature." It makes more sense to describe first how planets are labeled in of single solar system, and then in binary and multiple star systems, (since most exoplanets discovered are in single star systems). This would also make the section flow better given that the next sub-section is about circumbinary planets.

Secondly, there is no explanation that describes the larger picture of how nomenclature works for planets around a binary star system. For example, what are planets called around stars with a designation "Ab" or "Ac" etc. (Would the first planet then be called "Abb" or "Acb"?) It would make sense to include this information given the explanation of the WMC standard under the sub-section "Multiple-star standard" that the "Nomenclature" section begins with. I, however, do not know what this information is. Is there anyone who can add it?

Omnibus progression (talk) 22:10, 28 December 2012 (UTC)

There is nothing in the nomenclature section explaining what happens in the situation where a previously discovered and labelled exoplanet is later found not to exist, after other exoplanets in the same system have already been labelled with later letters. For example, if 82 G. Eridani c turned out to be a false detection, does 82 G. Eridani d then get instantly renamed to 82 G. Eridani c or is 82 G. Eridani c just erased from that star's planetary system description and the remaining planets allowed to keep their old labels, 82 G. Eridani b and 82 G. Eridani d, and newer planet discoveries labelled with letters after d? — Preceding unsigned comment added by 31.53.21.106 (talk) 02:45, 30 May 2013 (UTC)

Need to update text about TESS satellite at bottom of article

Now that TESS has been selected for launch, the text here is out of date.

I'm an exoplanet researcher and am generally pleased with the quality of this article. — Preceding unsigned comment added by 74.170.243.25 (talk) 18:39, 31 May 2013 (UTC)

  1. ^ ...