Talk:Fomalhaut b

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This article contradicts itself, at the top it says it orbits at the radius of Uranus, at the bottom it says at the radius of Eris. Jamie|C 23:20, 15 November 2008 (UTC)

It doesn't contradict itself, but itwas badly worded. The first time was the position relative to the inner edge of the debris disk, the second time it was the orbital radius. The comparison of the distance between the inner edge of the disk and a planet's orbital radius probably didn't help either: comparing the separation between orbits with an orbital radius isn't going to make visualising what is going on particularly easy. I've reworded it to make things clearer. Icalanise (talk) 23:28, 15 November 2008 (UTC)

As I know real distance is 119 AU. I'm talking about this phrase: "Fomalhaut b is an extrasolar planet orbiting the star Fomalhaut at a distance of approximately 115 AU". Check here please and change: (talk) 12:43, 17 November 2008 (UTC) (member from russian wikipedia)

The potential confusion here is whether we're talking about the current planet-star separation, or the semimajor axis of the orbit: according to the discovery paper, the semimajor axis of its likely orbit is 115 AU, however the current distance from planet to star is 119 AU. Icalanise (talk) 12:50, 17 November 2008 (UTC)

Alternate designations[edit]

Can someone provide a reliable source for the alternate designations? For example, does any source actually refer to the planet as "Alpha Piscis Austrinus b"? (Plus I thought the genitive case of "Piscis Austrinus" was "Piscis Austrini"...) Icalanise (talk) 21:04, 6 December 2008 (UTC)


I propose swapping File:Fomalhaut with Disk Ring and extrasolar planet b.jpg and File:Fomalhaut planet.jpg so that the former is in the infobox. I think the actual picture demonstrating its discovery is more interesting, and more striking, than the painting and deserves more prominence. Any objections? Olaf Davis (talk) 13:44, 2 August 2009 (UTC)

I say go for it! Icalanise (talk) 14:44, 2 August 2009 (UTC)
That image makes no sense. Is it showing a tiny planet skimming over the surface of a gigantic star ? At the radius of Uranus, or Eris ? Or is it showing the view of the planet, with the star in the background, and some little moon of the planet ?Eregli bob (talk) 07:29, 21 May 2012 (UTC)


From the The Extrasolar Planets Encyclopaedia I get the impression that Fomalhaut b is pretty much confirmed, not unconfirmed. Time to update, perhaps? Rursus dixit. (mbork3!) 07:06, 23 September 2012 (UTC)

Fomalhaut b is not confirmed at all. It has only been imaged at optical wavelengths, not in the infrared. A recent paper states that the observations are more consistent with that of a dust cloud, not a planet. Martin Cash (talk) 14:40, 28 September 2012 (UTC)
Martin, you were right that it was not imaged in the infrared - but it is NOW confirmed that the dust conglomeration around this planet is, indeed, around a planet. Thayne Currie et al., "Direct Imaging Confirmation and Characterization of a Dust-Enshrouded Candidate Exoplanet Orbiting Fomalhaut". - finally.
That said: I approve of your skepticism, and I agree that before this latest paper we just didn't know. Thanks for keeping some discipline around here--Zimriel (talk) 21:40, 25 October 2012 (UTC)
Not so fast - about a day after that one hit the arXiv, there is now [1] - apparently it is still consistent with the hypothesis that this is a dust cloud without an anchoring planet. The controversy over the nature of Fom b remains. (talk) 09:32, 27 October 2012 (UTC)
I have read this abstract (and now the paper too), and the abstract contains this: "we detect Fomalhaut b for the first time at the short wavelength of 0.43microns". The question of whether b exists, which is what Rursus originally asked, is settled; it's a bound clump of something that is genuinely in orbit, not a chance clump of dust and gas that just happened to appear on the images like the "face on Mars".
What remains is the question of what b is: a "massive planet" or some other "object". "Planet" seems more likely and most astronomers have been going with that. But I agree that we should at least mention that the alternative is possible. --Zimriel (talk) 21:48, 28 October 2012 (UTC)

Big changes[edit]

Hi! I can't argue with what you did - it's all pretty much what was on the article before now, except ... different. Do you have another Wiki handle or a talk page? --Zimriel (talk) 22:05, 21 December 2012 (UTC) Hi: Now I do. It's this one. — Preceding unsigned comment added by 2632cgn (talkcontribs) 05:01, 22 December 2012 (UTC)

orbital period[edit]

see here:
Mr. Kalas, the discoverer, calculated the new and corrected the period from ~870 to 2,000 years.
S. Dobrick (talk) 18:09, 14 January 2013 (UTC)

Yes check.svg Done - updated the infobox to include the newly calculated orbital period (2,000 years) - w/ several relevant references - entirely ok to rv/mv/ce of course - in any case - enjoy! :) Drbogdan (talk) 00:36, 29 January 2013 (UTC)


Judging by the NASA press release which gives periastron q and apastron Q of 4.6 and 27 billion miles respectively, the semimajor axis a and eccentricity e would be given by:

a = \frac{Q+q}{2} \approx 170 \mathrm{\ AU} and e = \frac{Q-q}{Q+q} \approx 0.7

The orbital elements in the infobox look more appropriate for the non-belt crossing orbit. (talk) 21:51, 22 January 2013 (UTC)

The updated orbital elements are now available on arXiv. [2] (talk) 23:37, 24 May 2013 (UTC)

Physical Characteristics[edit]

Should we remove this entire section since it was speculatively written based on data that is now quite superseded? — Preceding unsigned comment added by Autkm (talkcontribs) 20:35, 3 July 2014 (UTC)

Yep, you're right. If nobody objects, I'll do it in 48 hours, or if you want to do it right now, feel free to do so. Having read through the section, it appears to contain nothing but "if xxx, then yyy" with no evidence to back up the xxx part. StringTheory11 (t • c) 00:53, 4 July 2014 (UTC)
Apart from the paragraph on formation mechanisms, the current paragraph is based on measurements from refereed publications, which are specifically noted for each statement. Thus, the note about the section being outdated has been removed. For instance, the brightness ratio for Fomalhaut b (~2.7x10^-10) found by Kalas et al. (2008) is about the same (to within 10-25%, ~ within measurement errors) as can be inferred from subsequent publications like Currie et al. (2012). Likewise, evidence for Fomalhaut b's light being scattered starlight has been verified through multiple publications; mass limits for Fomalhaut b based on comparing its infrared non-detections to models mapping between the planet's luminosity and its mass (given an age) are also current, etc.