Talk:Circumbinary planet

And what about DP Leonis b? Isn't it confirmed as well? —Preceding unsigned comment added by 82.198.214.1 (talk) 17:21, 22 July 2010 (UTC)


 * Or Kepler-16b. Is there any data on proposed orbital dynamics on such a planet? One would think that the orbit would not be very uniform.Wzrd1 (talk) 19:37, 15 September 2011 (UTC)
 * Found an scientific article with all orbital parameters of Kepler-16 and planet b (last, 13th page, in image), added params to this page OverQuantum (talk) 11:04, 16 September 2011 (UTC)

I take issue with the word "confirmed" in this article. As of September 15, 2011, there has been only one "confirmed" circumbinary planet: Kepler-16b. It is the first time scientists have observed "direct evidence" of a planet orbiting binary stars. I would suggest this article should point this out.

Before Kepler-16b, scientists only inferred the existence of circumbinary planets. This is because of the effect planets have on the timing of the dual suns when they eclipse each other. Scientists inferred the existence of circumbinary planets by measuring the timing of the eclipsing suns. It was never before "confirmed" that these planets existed because factors other than planets can also effect the timing of these binary star eclipses. In March of 2011, when Kepler-16b was observed actually passing in front of its dual suns, it was the first time scientists were able to actually confirm the existance of a planet orbiting two stars. This information is available on the NASA/Kepler website and here: http://lightyears.blogs.cnn.com/2011/09/15/tatooine-gives-first-direct-proof-of-2-sun-planet/ — Preceding unsigned comment added by 157.166.167.129 (talk) 13:41, 16 September 2011 (UTC)


 * The diagram of the circumbinary system implies that the two stars are of equal mass. Typically, the two stars and the planet would be in three different orbits around the center of mass. 199.224.93.29 (talk) 21:34, 22 October 2022 (UTC)

Missing illustration
There is an urgent need for an illustration depicting the actual orbit of a circumbinary planet, as it's not clear from the text and not really self-evident, either. — Preceding unsigned comment added by 80.187.110.37 (talk) 20:13, 29 August 2012 (UTC)

PH1
Is a planet, not a star system! 178.26.56.174 (talk) 17:49, 18 October 2012 (UTC)

NSVS 1425
Two planets have been detected around NSVS 1425 system which have circumbinary orbit. Sources here:. --Artman40 (talk) 13:19, 19 October 2012 (UTC)

HW Virginis is not confirmed
http://arxiv.org/abs/1209.0608 Qemist (talk) 02:38, 25 April 2014 (UTC)

HD 202206 is not a stellar binary
Brown dwarfs are sub-stellar objects, not stars. Therefore the planet does not orbit two stars as required by the definition in the lede. Qemist (talk) 02:43, 25 April 2014 (UTC)
 * Not only substellar but also listed as a 17Mj planet in the exoplanet catalogs. Now deleted from this circumbinary list. Astredita (talk) 08:54, 25 April 2014 (UTC)

There are not seventeen confirmed systems
On the Abundance of Circumbinary Planets, quotes seven. Neither of the papers cited for the claimed seventeen appears to support it. Qemist (talk) 02:57, 25 April 2014 (UTC)
 * 1) That paper seems to be only about planets discovered by Kepler. 2)Ok, I've removed that sentence and the refs. Astredita (talk) 08:31, 25 April 2014 (UTC)
 * I've noticed that the word "confirmed" is used with great enthusiasm in several astronomy pages. To me confirmation is something that happens after discovery. When a second article is published, in the peer reviewed literature, with different authors, that independently verifies the discovery, then it is confirmed. However I see claims of planets being "confirmed" supported by links to discovery announcements, often not even peer reviewed. I think we need to adhere to accepted scientific conventions regarding confirmation.
 * But this opinion is not the accepted scientific convention in this case. Traditionally for a planet to be considered "confirmed" its mass (or rather minimum mass) had to be determined via radial velocity. This could be done by the discovery team prior to publication, hence why some discoveries refer to their planets as confirmed. Recently however the exoplanet community has taken a different tack with respect to (Kepler) transiting planets, where it is considered confirmed as long as you can sufficiently rule out false positives. For better or for worse that is the definition the scientists themselves are using. ChiZeroOne (talk) 22:57, 28 April 2014 (UTC)

Regarding the number of confirmed systems, Recent Kepler Results On Circumbinary Planets also cites seven. I don't think the exact number is especially noteworthy, and is obviously something that is prone to go out of date quickly. Qemist (talk) 06:42, 26 April 2014 (UTC)
 * As above, this is only Kepler discoveries. More were found before Kepler via radial velocity. But yes, the exact number isn't particularly important. ChiZeroOne (talk) 22:59, 28 April 2014 (UTC)

Intrabinary
What about "intrabinary" if it's between two stars that orbit at large distances? 128.237.193.65 (talk) 17:52, 23 May 2016 (UTC)

Planetary orbits
What are the actual or possible orbits? If the two stars are 'relatively close' and the planet 'relatively distant' will there be some form of elliptical orbit; if the stars are distant enough each may have inner planets orbiting one or the other (and possibly Lagrangian point planets and/or orbital locking) - but what other possibilities will there be? Jackiespeel (talk) 16:25, 15 June 2016 (UTC)

Diagram is a bit misleading
The orbit shown here is unstable unless the stars are very different in mass [correction it's not a fixed limit, depends on the mass ratio]. Robert Walker (talk) 22:13, 4 October 2017 (UTC)

Example, like orbit of Kepler 16b Robert Walker (talk) 22:17, 4 October 2017 (UTC)

Oh, sorry, cancel that, I see it says "not to scale", read it a bit too quickly. Still I think it might be better to show it to scale for a reasonable binary system, as it would still be easily readable. Robert Walker (talk) 23:15, 4 October 2017 (UT

... very misleading Needs a new diagram in line with text. stars of different sizes would orbit at different distances from the centre of mass. planet’s radius would be at least 4 times the solar radius any closer and the binary solar system would give rise to a unstable gravitational field on the planets orbit.