# Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

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## Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

A quadruple system with a transiting circumbinary planet.

Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System
http://arxiv.org/abs/1210.3612

We report the discovery and confirmation of a transiting circumbinary planet (PH1) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625.The 6.18 $\pm$ 0.17 Earth radii planet orbits outside the 20-day orbit of an eclipsing binary consisting of an F dwarf (1.734 +/- 0.044 Solar radii, 1.528 +/- 0.087 Solar masses) and M dwarf (0.378 +/0 0.023 Solar radii, 0.408 +/- 0.024 solar masses). For the planet, we find an upper mass limit of 169 Earth masses(0.531 Jupiter masses) at the 99.7& confidence level. With a radius and mass less than that of Jupiter, PH1 is well within the planetary regime. Outside the planet's orbit, at ~1000 AU, a previously unknown visual binary has been identified that is bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

Last edited by Sirius_Alpha on Sun Oct 28, 2012 1:03 pm; edited 2 times in total

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Sirius_Alpha

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Nice, been wondering if exoplanets would be found in systems with more than 3 stars.

The Ba/Bb binary seems quite wide (~60 AU), wonder if any S-type planets could have formed there, but I guess it's going to be hard to do an RV-search.

So what would the designation for the planet be - the paper seems to prefer to use PH1, but I guess it would be KIC 4862625 A(ab) b?

Lazarus
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Wow. Noteworthy. Circumbinary planets are growing in number

Edasich
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Lazarus wrote:So what would the designation for the planet be - the paper seems to prefer to use PH1, but I guess it would be KIC 4862625 A(ab) b?
I was wondering about that, too. I would use KIC 4862625 Ab or (A)b myself.

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Sirius_Alpha

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Right we've got a 4-star system with planets, now let's go do a deep-imaging search of Castor! We must have more multiplicity!

Lazarus
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## KIC 4862625 - Circumbinary Planet in a Quadruple System

Lazarus wrote:Right we've got a 4-star system with planets, now let's go do a deep-imaging search of Castor! We must have more multiplicity!

Haha

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Sirius_Alpha

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Independent discovery of KIC 4862625 and Kepler-47 systems:

A Gas Giant Circumbinary Planet Transiting an Evolved F Star Primary of the Eclipsing Binary Star KIC 4862625 and the Independent Discovery and Characterization of the two transiting planets in the Kepler-47 System
http://arxiv.org/abs/1210.3850

Lazarus
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Great success of the Planet Hunters initiative, maybe in future transiting missions the sharing of data with the public will become the norm.

On the other hand circumbinary planets deserve a dedicated topic, they are a different class of planetary systems in every sense.

Galzi
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Lazarus wrote:Right we've got a 4-star system with planets, now let's go do a deep-imaging search of Castor! We must have more multiplicity!

Well Castor System a 6 star system each group of the binary star by analogy of other circumbinary planetary systems can very possess they own planetary system,by the distance between stars in group can each of 3 binary star system have your own planetary system...

About deep-imaging search I don't know,but would be interesting search for planetary transit and TTV in the eclipsing binary system of Castor Ca and Cb,would be possible such study? if so would be a fascinating study on this 6 multiple star system personally my favorite

Daniel
SuperEarth

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Daniel wrote:About deep-imaging search I don't know,but would be interesting search for planetary transit and TTV in the eclipsing binary system of Castor Ca and Cb,would be possible such study? if so would be a fascinating study on this 6 multiple star system personally my favorite
Actually YY Geminorum (=Castor C) is one of the target systems for the DWARF project which aims to do just that...

Lazarus
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Wow I can't wait the results, very interesting to know that Part of the Castor star system is now been search for planets

Daniel
SuperEarth

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Well, once they claimed period change in the eclipsing pair YY Geminorum, indicative of the presence of a brown dwarf or a giant planet in 10 or more years orbit...

Edasich
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Lazarus wrote:So what would the designation for the planet be - the paper seems to prefer to use PH1, but I guess it would be KIC 4862625 A(ab) b?

EPE decided that just 'b' was sufficient.
http://exoplanet.eu/catalog/kic_4862625_b/

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Sirius_Alpha

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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

Overview of the detection and confirmation of PH-1 on the Planet Hunters Blog

Part 1, Part 2, Part 3, Part 4

Galzi
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## Re: Kepler-64 (KIC 4862625) - Circumbinary Planet in a Quadruple System (PH1)

PH1 ABCD a should be named but because the first planet starts as b not a what is wrong in my opinion so PH1 ABCD b

tommi59
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