Kepler-453 (KIC 9632895) - 6.2 Re circumbinary transiting planet in 240 day period

KIC 9632895 - The 10th Kepler Transiting Circumbinary Planet
http://arxiv.org/abs/1409.1605

Quote :

We present the discovery of KIC 9632895b, a 6.2 Earth-radius planet in a low-eccentricity, 240.5-day orbit about an eclipsing binary. The binary itself consists of a 0.93 and 0.194 solar mass pair of stars with an orbital period of 27.3 days. The plane of the planet's orbit is rapidly precessing, and its inclination only becomes sufficiently aligned with the primary star in the latter portion of the Kepler data. Thus three transits are present in the latter half of the light curve, but none of the three conjunctions that occurred during the first half of the light curve produced transits. The precession period is ~103 years, and during that cycle, transits are visible only ~8% of the time. This has the important implication that for every system like KIC 9632895 that we detect, there are ~12 circumbinary systems that exist but are not currently exhibiting transits. The planet's mass is too small to noticeably perturb the binary, consequently its mass is not measurable with these data; but our photodynamical model places a 1-sigma upper limit of 16 Earth masses. With a period 8.8 times that of the binary, the planet is well outside the dynamical instability zone. It does, however, lie within the habitable zone of the binary, and making it the third of ten Kepler circumbinary planets to do so.

1. Kepler-16 b
2. Kepler-34 b
3. Kepler-35 b
4. Kepler-38 b
5. Kepler-47 b
6. Kepler-47 c
7. Kepler-64 b
8. Kepler-413 b
9. Kepler-47 d??

http://arxiv.org/pdf/1404.5617.pdf

May be KIC 6504534b  (Table 3)

From the introduction to the paper:

Quote :

To date, nine transiting circumbinary planets have been discovered, residing in seven systems: Kepler-16b (Doyle et al. 2011), Kepler-34b and 35 b (Welsh et al. 2012), Kepler-38b (Orosz et al. 2012b), Kepler-47b and c (Orosz et al. 2012a), Kepler-64b (Schwamb et al. 2013 and simultaneously Kostov et al. 2013), Kepler-413b (Kostov et al. 2014), and Kepler-47d (Orosz, in prep).

(Emphasis in bold mine)

...but enough of Kepler-47d, back to KIC 9632895: seems there's a possibility this is a rather low-density planet, given the mass limits and the radius value. The 1-σ limit (16 Earth masses) is definitely a bit on the low side:

Quote :

Taking 32 M_⊕ as a 2-σ upper mass estimate, the mean density is then smaller than 0.75 g cm³ [sic] with 95% confidence. If the mass is truly lower than 16 M_⊕, then the density is < 0.38g cm³ [sic] and KIC 9632895 is an unusual low-mass and low-density planet.

Now it has a Kepler designation: Kepler-453 b.
http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=Kepler+453+b&type=CONFIRMED_PLANET

Thanks for that. I probably wouldn't have noticed it without your efforts here. I've updated the thread title.