Talk:Binary star

Visual Binaries section- Role of Star Brightness in Hindering Identification
"The brightness of the two stars is also an important factor, as brighter stars are harder to separate, due to their glare, than the dimmer ones."

Not being an astronomer, I'm loath to immediately change this myself, but this unsourced statement seems plainly wrong. Aperture or exposure time can easily be reduced, cutting down on glare artifacts. The correct statement is probably that if there is a large difference between the luminosities of the two stars, then the faint secondary can be more difficult to detect due to the overwhelming glare of the primary. Undomelin (talk) 07:28, 25 January 2013 (UTC)


 * I *am* an astronomer and the statement is wrong. It may indeed intend to refer to binaries with large brightness difference between the components, but it doesn't say that. Lithopsian (talk) 16:54, 19 March 2013 (UTC)

Needs a Trinary Star System Animation
This is an outstanding article, but you have to admit that an animation of a trinary star system would be extremely cool and really should be added.

75.166.179.110 (talk) 19:01, 21 March 2010 (UTC)

Fictional Usage
Would it be plausible to add a section on the fictional Mirrodin installment of Magic, The Gathering, which features a multi-star system? —Preceding unsigned comment added by 4.159.176.131 (talk • contribs) 00:16, 29 August, 2006 (UTC)

The fiction section was getting a bit large (especially since the article is quite big itself), so I split it off today. Nick Mks 19:55, 4 December 2006 (UTC)

Binary star collision
Is it possible for a binary star to collide with its companion? After all, their orbits do overlap: [] —Preceding unsigned comment added by Just James (talk • contribs) 12:56, 6 October, 2006 (UTC)


 * No. Since they orbit their common center of mass, they are always at opposite sides of the orbit (exactly as in the last animation). They can fuse together though, if they spiral in towards each other, as explained in the article. Thanks for bringing my attention to these nice animations. Nick Mks 10:56, 7 October 2006 (UTC)


 * I however, have found a different answer. Sometimes binary companions can and do collide.  It happens with older stars of large mass.  Some gamma-ray bursts, for instance, are caused by two neutron stars in a binary system colliding.--Sgcgirl52 08:47, 12 December 2006 (UTC)


 * Exactly, as I mentioned above binaries can spiral into each other and eventually merge. That's what you are referring to and this is also in the article. What Just James asks is whether they could undergo a sudden freak collision due to the fact that their Kepler orbits intersect. This is of course impossible, since orbiting bodies are always at opposite ends of their orbit. Nick Mks 18:57, 12 December 2006 (UTC)


 * I was unaware that Just James was only refering to the companions colliding due to their Kepler orbits. I assumed that he was refering to colliding in any matter and was just trying to clarify that the two can be in a degenerative orbit and eventually collide. --Sgcgirl52 22:33, 12 December 2006 (UTC)


 * I understand, and I appreciate your input. I can actually only guess that he refers to that because he said After all, their orbits do overlap. That's why I assume he means a sudden collision. Nick Mks 08:32, 13 December 2006 (UTC)


 * According to Isaac Newton, Principia, Book I Sect. 11 ("The motion of bodies drawn to one another by centripetal forces") the orbits - seen relatively to the barycenter - do not overlap; rather the bodies rotate in "concentric ellipses" (Newton l.c., Prop. 58 Corollary 1). The view of seemingly overlapping orbits may be due to the astronomer's perspective, as is the view of sun seemingly wandering about the earth from morning to evening. Ed Dellian 84.144.128.120 (talk) 13:03, 15 May 2017 (UTC)

Vandalism
As from now, I am discontinuing my efforts to limit vandalism to this article (which I got featured last spring). Without the requested support from admins, this is becoming an impossible task. Nick Mks 18:36, 8 November 2006 (UTC)
 * Despite my vow not to, I reverted vandalism today. I pretty much had to, because it had been there for almost 24 hours, and I doubt whether it would have been removed at all. The degeneracy of scientific articles lately is quite obvious... Nick Mks 19:56, 19 November 2006 (UTC)

Occurrence of multiple systems
This line in the article is intriguing: "Recent research suggests that a large percentage of stars are part of systems with at least two stars" Could a footnote or link be added to explore it? Thanks, John Sweeney —Preceding unsigned comment added by 24.25.230.141 (talk • contribs) 18:56, 29 November, 2006 (UTC)


 * Well, this is indeed a very hot topic in astrophysics, so it is quite difficult to give a complete and correct answer. A good and recent reference is the one in the article: . You can also browse ADS with some relevant keywords for more. Nick Mks 21:16, 29 November 2006 (UTC)


 * Well, the link that you have given supports past hypotheses and ADS did not give any relevant information to me either. Do you have any stronger reference? Really, stated in this way without any reference, it sounds very ... trust-worthless, let's say.

Simple Question
I apologize if it sounds like a very basic question, but how would the two stars on a binary system appear on the sky of an Earth-like planet orbiting one of the two suns and relatively far from the other ? Specially, how would sunset/sunrise, day/night look like ? 161.24.19.82 17:29, 29 May 2007 (UTC)

Nemesis/Sun Relationship
Shouldn't the Sun/Nemesis hypothesis be added in some way to the article? Scientists think that our Solar System is a binary-star if Nemesis is out there beyond the Oort Cloud. Spark Moon 16:25, 2 June 2007 (UTC)
 * Scientists think our Sun does NOT have a binary companion. The Nemesis hypothesis is from 1984 and none of the infrared surveys have found it. -- Kheider (talk) 22:23, 29 December 2012 (UTC)
 * But there seem to be many people who believe or at least claim that Nemesis or Nibiru exists. While their beliefs don't seem to me to be based on observation / deduction, the fact does exist that there are people who claim this. So I think this article could appropriately carry a short section on the subject. At the very least it's fun to consider whether the Sun might have an undiscovered, gravitationally linked companion. Friendly Person (talk) 15:52, 3 December 2020 (UTC)

Two stars
The first sentence says A binary star is a stellar system consisting of two stars orbiting around their center of mass. And right two it there is a picture with only 1 star and a blackhole. I know blackholes were stars before they died, but I think the first sentence ain't right. 08:33, 5 June 2007 (UTC)

DDEB - Double-lined eclipsing binary
Reading this [AJ paper], they claim that NSVS01031772 is a DDEB type binary. Looking on this page, it does not mention it. This is the first time I seen this term, wondering if any of you know what this means. It also states that these objects are scarce. And that the first 2 low-mass ones discovered are CM Dra & YY Gem. What makes NSVS01031772 unique is that both stars are of stellar metallicity. I will try rereading the paper to see if I missed anything. Thanks, CarpD 6/22/07.

I looked at the paper. I think DDEB is just their non-standard notation for a double-lined system, so not worth noting. I couldn't find any other papers using this notation on a quick search. Timb66 07:39, 23 June 2007 (UTC)

Gravitational Lensing
I think there should be a bit about how gravitational lensing can make one object look like two (or more). For example the Twin Quasar is a gravitationally lensed object that looks like two. --72.39.35.178 (talk) 18:21, 9 August 2008 (UTC)

Article Structure
This whole article in a factually an absolute mess, which I have made a significant improvement n "Terminology" using primary sources.

There are too missing references to much of the quoted text.

The status of the text as a feature article should be removed until this issues are fixes. The peer review made in 8th June 2006 is far out of date, and the whole article has been significantly modified. It is important this page is fixed, as it hinges on other binary and double stars being referenced in other Wikipedia articles. (estimate +1000)

This also needs to be integrated with the Wikipedia pages on Double stars and Multiple stars

Arianewiki1 (talk) 04:11, 20 August 2008 (UTC)

Serious Problems with Astronomical Definitions
The current version of this article is greatly improved here. I have great appreciation for Spacepotato's efforts in correction some glaring mistakes and investigating various references.

However, I have grave concerns with the use of terms for "double stars" and "binary stars" - especially the distinction of the two.

The persistent and wrong view of "stellar systems" throughout the astronomy articles in "Wikipedia" shows the lack of understanding about the nature multiple gravitational systems. Namely, single stars, double stars, multiple stars, associations, open star clusters and globular star clusters. These divisions are not just based on numerical counts, but also on their own internal dynamics. Such distinctions are important for their evolution, stability and behaviours.

Double stars, Multiple stars, Associations, Open Star Clusters and Globular Star Clusters are not just singular objects, by are also distinct subjects in observational and theoretical astronomy.

in this instance, "Double stars" are the generic term for these objects AND the topic of such gravitational celestial bodies. Observationally, both "Binary stars" and "optical pairs are typically a subset of subject "Double stars." "Double stars" use as a term is especially important by visual observers, who are making so-called "measures" to determine if "double stars" are either binaries or optical pairs. Arianewiki1 (talk) 09:52, 23 August 2008 (UTC)

Over time this distinction is made by the apparent motion of components. Shorter period binaries have been learnt rather quickly. Ie. William Herschel with Gamma Virginus (Porrima) and Castor, but the majority remain uncertain if they are attached gravitationally or not. These are commonly called "double stars" or "visual double stars" - 'pairs' if you must. They are not umbrella "stellar systems", they are actually important distinct classes of astronomical objects. The same problem is with "Multiple stars", they are a class of objects. "Multiple star systems" is simply a redundant term, which is both confusing and rarely used. (Read whole discussion in the page stellar systems. This reads like an agenda produced by some individual writers. Sadly, this usage is historically has been rarely used, and through the nomenclature of the I.A.U.


 * Wikipedia writers should refer the

Another is Lortet, M.-C., Borde, S., Ochsenbein, F. 1994, The Second Reference Dictionary of the Nomenclature of Celestial Objects, A&AS, 107, 193 (

Unless writers are prepared to adopt common usage terms for astronomical classes of objects, then most of these Wikipedia articles will continue to be rejected as portraying how such systems are actually investigated and understood. —Preceding unsigned comment added by Arianewiki1 (talk • contribs) 09:52, 23 August 2008

Optical doubles v. binary stars
ON 20 December 2008 Spacepotato (Talk | contribs) (50,279 bytes) said "Copyedit again. Also, incorrect to equate visual binary stars with binaries whose orbits are known." Please. This is not what I'm actually saying!!!!!! The statement is that "binary stars with orbits" are a sub-set of "visual DOUBLE stars" !! As I said before there are are THREE types of (visual) Double Stars and NOT just TWO. These are Binary stars, Optical Doubles or pairs, and THOSE NOT DETERMINED AS EITHER BINARIES OR OPTICAL DOUB:ES. Such indeterminate systems are called by observers as PAIRS or "globally" as DOUBLE STARS. In fact, the majority of (visual) double stars 98% are NOT absolutely known to be binaries, while perhaps about 30% have been determined as very likely optical. The rest of the systems are unknown attachment. So what should YOU call these???? They are (c. 68% of them) neither established binaries nor optical doubles! But I do see your point of view, and basically where you are coming from. Yes, theoretically there are can only be binaries or non-binaries (optical double stars), but to the reader it leaves the impression that we already know for certain they are all one or the other. Clearly the real truth is we don't really know where the majority fall - it is actually the driving force for the last two hundred years or so now behind basic double star research. Arianewiki1 (talk) 06:22, 20 December 2008 (UTC)
 * Although it is true that many pairs are not known to be either physical or optical, this was not what my statement was intended to point out. Rather, my point was that pairs might be known to be physical although their orbits are not known.  To quote Heintz : "If the component proper motions nearly equal each other, leaving a considerably smaller difference as a relative motion, the pair is very probably a physical one, and this conclusion becomes a virtual certainty if the spectroscope also shows the radial velocities to be nearly equal."  For examples of this, you can consult the Washington Double Star Catalog.  Many pairs are tagged with a V, indicating that they are physical, despite the fact that their orbits have not been determined.  The pair STF 3060AB, for instance, is such a pair.  So, it's not correct to say that only 2% of visual double stars are known to be physical just because only 2% of them have their orbits listed in the Sixth Catalog of Orbits.
 * Spacepotato (talk) 03:27, 21 December 2008 (UTC)

Merger proposal
As I suggested at AfD (comment 21:29, 5 March 2011), the editors unhappy with Hot companion would do more good pouring their energy into moving any relevant content into this article and redirecting. [Clarification: I am neutral on the merge. I'm just trying to move the project along.] - Simon Dodd { U·T·C·WP:LAW } 13:36, 11 March 2011 (UTC)

Work needed
Hi everyone - Unfortunately, this article has not kept up with featured article standards in the years since it's promotion. If it is to remain a featured article, some rather significant work is needed. The major issues that caught my eye include:
 * References needed banner in Spectroscopic binaries section
 * There is quite a bit of other unreferenced information. See, for example, the third paragraph of Eclipsing binaries, the second and fourth paragraphs of Astrometric binaries, the second and third paragraphs of Configuration of the system, much of the Astrophysics section and its subsections, etc. These are just examples, there are other areas, too.
 * Reference formatting needs some work. Web references need access dates. Books need page numbers (see, for example, the Nigel Henbest book). Consistency should be checked (see, for example, refs 5 and 6). Are page numbers for books given first or later in the reference? These are just examples, and a full check is needed for consistency, completeness, and reliability.
 * Text should not be sandwiched between images.
 * Removed redundant image and moved movie to right to eliminate sandwiching. Stigmatella aurantiaca (talk) 03:35, 28 November 2013 (UTC)


 * Three dead links, see the report.
 * Removed one of the three dead links; two remain for which replacements need to be found. Stigmatella aurantiaca (talk) 03:59, 28 November 2013 (UTC)

If, at the very least, the major issues are not addressed, this article will need to go to WP:FAR. Dana boomer (talk) 14:25, 18 November 2013 (UTC)
 * I also think that there should be a section which divides binary stars into three categories:


 * Close binaries: Stars which orbit so close to each other that they affect their stellar evolution significantly. (for an example: Kepler-16 A and Kepler-16 B)
 * Medium-distance binaries: Stars which do not affect each other's stellar evolution significantly but have a major influence on each other's astrospheres, circumstellar disks and the stability of regions which can form planets. (for an example: Alpha Centauri A and alpha Centauri B, Proxima Centauri not included)
 * Wide binaries: Stars which do not affect each other significantly, not do they affect the stability of each other's astrospheres and gravitational stability of planetary bodies inside their astrospheres. They still affect the orbits of distant comets. (for an example ADS 16402 A and ADS 16402 B

These characteristics are very important when it comes to evolution of stars and planets in multiple star systems. --Artman40 (talk) 23:37, 5 December 2013 (UTC)

Post-common-envelope binary
Two articles discussing the star RR Caeli describe it as a post-common-envelope binary, a red link. As far as I can see, these are the only occurrences of the term in the English Wikipedia. Should the concept be explained, probably in this article, or should we get rid of it? J S Ayer (talk) 01:25, 21 February 2014 (UTC)

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Binary star system categories
I removed this material from the Discovery section. It did not seem appropriate where it was placed, and the reference was inaccessible. I see a National Radio Astronomy Observatory news release about these results, but no other decent secondary sources. John Tobin and his team found that there are two types of binary star system categories: there either being separated between a distance between less than 300 astronomical units or greater than 1000 astronomical units(Hall, Shannon).

Stigmatella aurantiaca (talk) 18:15, 22 November 2016 (UTC)
 * Something funky with your link. Here is a direct link to a paper with results from this study. Pretty abstruse stuff. Also not what the article stated anyway. Lithopsian (talk) 18:22, 22 November 2016 (UTC)
 * Fixed the link. Sorry about that. :-( You are right about the article being somewhat abstruse. Stigmatella aurantiaca (talk) 19:37, 22 November 2016 (UTC)

When is a simulation not a simulation?
Before a series of animations:
 * Images are representative, not simulated.

The phrase "not simulated" usually means it's the real thing. Let's find another wording. How about "These animations do not attempt to represent any specific real system"? —Tamfang (talk) 19:51, 2 January 2017 (UTC)

Which are both visual and spectroscopic
Binary_star says "Binary stars that are both visual and spectroscopic binaries are rare, and are a precious source of valuable information when found" but it doesn't list any or have a source we can refer to. Should we note some here or where ? - Rod57 (talk) 18:28, 16 January 2017 (UTC)
 * See https://aas.aanda.org/articles/aas/pdf/2000/14/ds9259.pdf — Preceding unsigned comment added by 31.53.52.160 (talk) 07:16, 5 June 2017 (UTC)
 * This mentions about 40 binaries. — Preceding unsigned comment added by 31.53.52.160 (talk) 07:31, 5 June 2017 (UTC)

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"often appear to the unaided eye as a single point of light"
The article currently claims that


 * These systems, especially when more distant, often appear to the unaided eye as a single point of light, and are then revealed as multiple by other means.

but don't they always appear to the unaided eye as a single point of light?

(Some of them can be resolved with optical telescopes; I wonder if someone misunderstood some reference to "visual binaries" and thought that they were visible to the naked eye?)

—Ruakh TALK 02:41, 21 April 2018 (UTC)


 * Definitely not always, but perhaps nearly always would be more accurate. Not many known orbiting pairs can be resolved with the naked eye.  Lithopsian (talk) 11:01, 22 April 2018 (UTC)


 * Do you have any examples handy of ones that can? —Ruakh TALK 05:05, 3 December 2018 (UTC)


 * ζ Reticuli has an inferred orbit, very long obviously. There are a number of other common proper motion pairs resolvable to the naked eye, but orbital motion is difficult to detect.  ε Lyrae, θ Tauri, μ Scorpii, and α Librae are all binaries relatively easy to split with the naked eye.  β Capricorni is a real challenge without binoculars.  Proxima Centauri is an interesting case.  It has a known orbit and is so widely separated from α Centauri that you'd hesitate to even call them a double star.  Proxima has recently been seen to produce a superflare bringing it to the edge of naked-eye visibility and it is estimated that these should occur several times a year.  Lithopsian (talk) 15:19, 3 December 2018 (UTC)


 * Interesting; thank you! —Ruakh TALK 05:11, 14 December 2018 (UTC)


 * I've noticed binary system : binary star - I just would like to propose with all reason that the former must be the accurate description, the latter must be made redundant because the word star is the singular (the term binary star is a contradiction - binary stars) - the former is a linguistic conflict which has no solution except for the naked eye ruling the definition, but in reality we all know the naked eye observation isn't the reality - why does the article maintain the earlier defunct identification? Autonomous agent 5 (talk) 20:52, 8 June 2021 (UTC)
 * as the previous user aptly describes "..the unaided eye.." - surely unaided can't be the current reality, because the internet is surfeit, or at least equipped, with aid in the form of information 20:57, 8 June 2021 (UTC)
 * "star" is archaic, anachronistic... 21:10, 8 June 2021 (UTC)
 * We're here (at Wikipedia) to report the world, not fix it. If people call them binary stars then we have to use that term.  When people have stopped calling them binary stars then we can too.  This comment seems out of place in this section.  Perhaps if you put it in a new section, there can be a discussion of which is the most commonly-used term in the real world and which we should prioritise here.  Note that binary system is a separate article about a more general topic.  Lithopsian (talk) 14:52, 10 June 2021 (UTC)
 * thanks; I'll consider for a time your reply: regards, Autonomous agent 5 (talk) 23:50, 10 June 2021 (UTC)

Percentages
It would be useful to have information in this article about percentages: What fraction of stars are optical binaries, and what fraction are true double stars? Doubtless, there are estimates. Friendly Person (talk) 15:42, 3 December 2020 (UTC)

Proper crediting of the video "artist's impression of an eclipsing binary"
The video used in this article is not properly credited. I found it on https://www.eso.org/public/videos/eso1311b/, credited as "ESO/L. Calçada". A reference to this page is basic etiquette of crediting scientific works. 178.165.191.108 (talk) 15:34, 11 June 2023 (UTC)
 * Wikipedia article space generally does not include credits, its not considered encyclopedic information. See MOS:CREDITS. Fountains of Bryn Mawr (talk) 20:19, 11 June 2023 (UTC)