Talk:Double star

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Why does this page exist?

Untitled

If Double star is another term for binary star, then why don't we turn this page into a redirect instead of an article? CDClock 03:07, 20 August 2007 (UTC)[reply]

It's my understanding that true binary stars comprise about half the stars (some sources say more, others say less) that we see. In any case, they are not the "vast majority" asserted in the article. 71.131.210.63 14:40, 12 August 2006 (UTC)[reply]

Why does it exist? I wonder why too. Binary star contains everything that this page have and a lot more. ... said: Rursus (bork²) 13:02, 15 May 2009 (UTC)[reply]

No, this page because double stars include stars that appear near each other as seen by direction from earth, optical doubles are those who are near each other by chance, and they have no physical connection. Binary stars are physically connected, and so are included among double stars. Relevant links to be added. ... said: Rursus (bork²) 15:38, 15 May 2009 (UTC)[reply]

delete

This article is worthless as it stands. Actual, gravitationally bound binaries are the only type worth discussing in an article. So what if two stars "appear close together?" What if three stars appear close together--do we need a "triple star" article, too? Or four? Or five? Oh wait--we already have an article about that. It's called, Star cloud. But more significantly, there already is an article about binary stars. We do not need a more general article about stars that appear close to one another, and may or may not be gravitationally related. For that, we have the article about star clouds. Two stars appearing close together is not fundamentally different or even interesting. -69.47.186.226 07:34, 29 August 2007 (UTC)[reply]

I think that a double star is just two stars that are close together. Sometimes that is interesting, such as with Mizar and Alcor. I do not think, though, that a double star and a binary star are synonymous. --Segregold 05:20, 30 August 2007 (UTC)[reply]

It can be made interesting in the sense of how astronomers determine whether a double star is physically connected. I.e. whether they are at about the same distance and share a common motion through space. An example is proxima centauri, where it remains uncertain whether it is part of the alpha centauri system or just happens to be a member of the same moving group. It's also important to differentiate the term from binary star, because many pairs are catalogued as double stars, which some may mistake as indicating they are binaries. (That has happened here on Wikipedia.) Providing this article also provides a link point separate from binary star.—RJH (talk) 20:43, 25 August 2010 (UTC)[reply]

Rewritten

It seems this page was completely rewritten by one editor. It has been reverted and should now make more sense. Vsst 18:06, 5 September 2007 (UTC)[reply]

Multiple Stars

Multiple stars are classically sub-class of double stars, both historically and currently. I.e. If it were not called the Washington Double Star Catalogue, therefore why does it list multiple stars? I accuse Spacepotato of gross manipulation of the definition of double star. (If you want to have the decided on some arbiter, then I am prepared to go the distance, because you clearly don't know what you are actually talking about.) User:Arianewiki1 07:34, 16 January 2009 (UTC)[reply]

To quote Aitken (The Binary Stars, Dover, 1964, p. ix): "The term double star is of earlier origin...It is still occasionally applied to this [ν Sagittarii] and other pairs of stars visible to the unaided eye, but is generally used to designate pairs separated by not more than a few seconds of arc and therefore visible as two stars only with the aid of a telescope." For him, then, a double star is a pair of stars. As for the Washington Double Star Catalog, the USNO writes [1]: "The Washington Double Star Catalog (WDS) maintained by the United States Naval Observatory is the world's principal database of astrometric double and multiple star information." So, here as well, double stars do not include multiple stars. Of course, it may be that historically double and multiple stars have been studied together, but that is not to say that the objects themselves are the same. Spacepotato (talk) 22:54, 16 January 2009 (UTC)[reply]

There are so many errors and inconsistencies that this entry is mostly a waste of time fixing. The new entries by Spacepotato, and the continuous his reverts is totally unacceptable - who is still prepared to delete whole sections, even though they are relevant and are placed for clarity. I have fixed these same problems on three separate occasions, and will not be doing this again. User:Arianewiki1 07:34, 10 March 2009 (UTC)[reply]

Regarding accusations of this and that, try to follow WP:GOODFAITH! That's a wikipedia policy. Find the error of individual edits, and object by citing sources that oppose the statements in the article, please refrain from attacking individuals. Besides Spacepotato have been around for a time, so his edits are generally knowledgeable. ... said: Rursus (bork²) 13:09, 15 May 2009 (UTC)[reply]

Redundancy

The page says, 'if the relative motion is small compared to the common proper motion of both stars, it may be concluded that the pair is in mutual orbit as a binary star.' Is this correct? I can't see how the proper motion is relevant, surely only their relative motion (and perhaps proximity) are relevant. 174.61.204.120 (talk) 05:17, 17 January 2015 (UTC)[reply]

Yes. Arianewiki1 (talk) 05:21, 17 January 2015 (UTC)[reply]

External links modified

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Mizar and Alcor, and Alpha and Proxima Centauri

A few months ago I added a sentence saying that Mizar and Alcor (in the Big Dipper) are possibly a "binary" star (actually there are six stars in all, but they appear as two to the naked eye). Arianewiki1 took that out with the comment that Mizar is not a 'known' binary. But I did not write that Mizar was a known binary. I wrote that Mizar and Alcor are possibly a binary. So what I said was correct.

Just add a citation and there can be no complaints. Otherwise it is just asking to be taken out again. Lithopsian (talk) 09:43, 4 September 2018 (UTC)[reply]

He or she also moved the Alpha Centauri - Proxima system from the list of visual binaries to the list of "Uncertain" cases. But it has now been established that Proxima is gravitationally bound to Alpha Centauri. The reference is in the article Proxima.

So I intend to put my changes back in.

Eric Kvaalen (talk) 08:58, 4 September 2018 (UTC)[reply]

The mysterious 'Lambda' ('λ') catalogue of double stars

To all observers of double stars. Pages 285 to 319 in T.W.Webb's Celestial Objects For Common Telescopes (Volume 2: The Stars) show an interesting index of double stars with coordinates for Epoch 2000. In this index, a certain 'Lambda' (a designation code from one of the many double star observers) is mentioned about a dozen times. Now, who is (or was) 'Lambda'? (λ). Below you see the printed examples from the 'Lambda' catalogue: λ 32 (RA 3:47.9), λ 88 (RA 7:48.9), λ 91 (RA 7:55.7), λ 96 (RA 8:12.5), λ 108 (RA 9:0.3), λ 115 (RA 9:37.1), λ 140 (RA 11:56.7), λ 176 (RA 13:20.5), λ 228 (RA 15:23.2), λ 249 (RA 15:47.6), λ 316 (RA 17:0.4), λ ? (RA 17:6.4), λ 320 (RA 17:12.2), λ 342 (RA 17:53.3). All examples are located in the southern celestial hemisphere. Is this 'Lambda' catalogue in some way related to T.J.J.See's catalogue? (the numbers of these 'Lambda' double stars seem to correspond with those of T.J.J.See's double stars). Danny Caes, Ghent-Belgium. — Preceding unsigned comment added by 2A02:1812:151F:5500:6DB0:E10C:2CAE:9FF2 (talk) 15:30, 19 April 2019 (UTC)[reply]

Yes, it is. The λ designations refer to entries in Discoveries and Measures of Double and Multiple Stars in the Southern Heavens, presumably referring to the Lowell observatory. Given the acronym SEE in more recent times. Lithopsian (talk) 17:21, 19 April 2019 (UTC)[reply]

It is the old designation double star assigned to all T.J.J. See discovered pairs, which appears as a cite in "Double Stars" by Heintz (1978) pg.11. I believe See himself used λ for his own discoveries[2], but reason is lost to us because of a fire in 1897 at Lowell Observatory that destroyed some of the earlier manuscripts. The whole catalogue is spread across several sources, not just one, where λ₁ is the first catalogue, and the others added, but the usage just became λ.

There are a total of 515 SEE pairs, with 417 being recognised today (up to SEE 513) and they have been arranged in order of Right ascension (1900). Declination range is −17 to −60 degrees south.
Most of these are usually bright stars with possible faint to very faint companions. There are 65% of these companions are below 12th magnitude or 20% below 13th and 10% below 14th.
Half of them exceed 10 arcsec.

These older designations continued until the1980s when digital version of double star catalogues appeared. On-line version here[3]. R.T.A. Innes created the southern star list in Webb in 1920, adding the bright pairs. Arianewiki1 (talk) 00:31, 20 April 2019 (UTC)[reply]

Lambda and T.J.J.See

Thank you Lithopsian (!) and Arianewiki (!) and perhaps many more readers of this quest (that's VERY interesting info!!!). I must say, I like this ancient booklet from T.W.Webb (Celestial Objects for Common Telescopes, Volume 2) very much, but it is necessary to investigate these yellowish pages the way a detective would do (bit by bit). I underlined the names of all double star observers mentioned in that booklet (fluo-marker) because there's no alphabetic name-index in it (I did the same in Burnham's Celestial Handbook, Vols 1, 2, 3). Danny Caes, Ghent-Belgium (explorer of astronomical catalogues, and dedicated contributor of the Wikipedia page 'List of Astronomical Catalogues'). — Preceding unsigned comment added by 2A02:1812:151F:5500:6DB0:E10C:2CAE:9FF2 (talk) 06:56, 20 April 2019 (UTC)[reply]