KOI-1299 / Kepler-432 : Eccentric, transiting warm Jupiter around red giant

KOI-1299 b: a massive planet in a highly eccentric orbit transiting a red giant
http://arxiv.org/abs/1410.2999

Spectroscopic confirmation of KOI-1299b: a massive warm Jupiter in a 52-day eccentric orbit transiting a giant star
http://arxiv.org/abs/1410.3000

Red "Giant", this is clearly still a subgiant.

I don't follow. The star has a log g of 3.35 ± 0.07 cgs, which is lower than that of a subgiant and pretty typical for an early giant.

I'd like to point out the humour in this situation. Two papers confirming the same planet, published on the same day, made by different teams, using the same spectrograph independently. The apparent lack of communication is extraordinary,

Anyway, this is a pretty interesting result. The planet occupies a rather poorly populated region of the period diagram for giant planets (the "period valley"), regardless of the star's evolutionary state. Short period planets around giants do seem to exist with modest rates of incidence, so the next step is to characterise the population. There are a fair few more active KOIs with low surface gravities, so I expect at least a few more planets around giants will come from Kepler, even with a high false positive rate.

Shellface wrote:

I don't follow. The star has a log g of 3.35 ± 0.07 cgs, which is lower than that of a subgiant and pretty typical for an early giant.

I'd like to point out the humour in this situation. Two papers confirming the same planet, published on the same day, made by different teams, using the same spectrograph independently. The apparent lack of communication is extraordinary,

Anyway, this is a pretty interesting result. The planet occupies a rather poorly populated region of the period diagram for giant planets (the "period valley"), regardless of the star's evolutionary state. Short period planets around giants do seem to exist with modest rates of incidence, so the next step is to characterise the population. There are a fair few more active KOIs with low surface gravities, so I expect at least a few more planets around giants will come from Kepler, even with a high false positive rate.

Perhaps to insure independent detection and confirmation.

More about KOI-1299: additional non-transiting planet.

KOI-1299: A red giant interacting with one of its two long period giant planets

Quote :

We report the discovery of KOI-1299b, a giant planet (M_b = 5.41^{+0.32}_{-0.18} M_{\rm Jup}, R_b = 1.145^{+0.036}_{-0.039} R_{\rm Jup}) transiting an evolved star (M_\star = 1.32^{+0.10}_{-0.07} M_\odot, R_\star = 4.06^{+0.12}_{-0.08} R_\odot) with an orbital period of P_b = 52.501134^{+0.000070}_{-0.000107} days. Radial velocities (RVs) reveal that KOI-1299b orbits its parent star with an eccentricity of e = 0.5134^{+0.0098}_{-0.0089}, which we also measure independently with asterodensity profiling (e=0.507^{+0.039}_{-0.114}), thereby confirming the validity of asterodensity profiling on this particular evolved star. The well determined planetary properties and unusually large mass also make this planet an important benchmark for theoretical models of super-Jupiter formation. Long-term RV monitoring detected the presence of a non-transiting outer planet (KOI-1299c; M_c \sin{i_c} = 2.43^{+0.22}_{-0.24} M_{\rm Jup}, P_c = 406.2^{+3.9}_{-2.5} days), and adaptive optics imaging revealed a nearby (0.87"), faint companion (KOI-1299B) that is a physically bound M dwarf. The host star exhibits high S/N asteroseismic oscillations, which enable precise measurements of the stellar mass, radius and age. Analysis of the rotational splitting of the oscillation modes additionally reveals the stellar spin axis to be nearly edge-on, which suggests that the stellar spin is likely well-aligned with the orbit of the transiting planet. Despite its long period, the obliquity of the 52.5-day orbit may have been shaped by star-planet interaction (SPI) in a manner similar to hot Jupiter systems, and we present observational and theoretical evidence to support this scenario. Finally, as a short-period outlier among giant planets orbiting giant stars, study of KOI-1299b may help explain the distribution of massive planets orbiting giant stars interior to 1 AU.

Both planets in orbits of substantial eccentricity too. Also noteworthy for the first demonstration of agreement between asterodensity profiling and radial velocity orbits for a giant star.

This should be migrated to the appropriate thread, no?

Anyway, this is now the third paper confirming KOI 1299 b, which may be a record for the number of independent "first" confirmations of a planet. To summarise;

• Ciceri et al. used the CAFE spectrograph at moderate precision (~50 m/s) over ~400 days, which could detect b but not c due to precision issues.
  
• Ortiz et al. used CAFE at higher precision (~20 m/s) and FIES (~7 m/s) over ~100 days. This detected b more precisely, but not c due to poor time coverage.
  
• Quinn et al. used TRES (~30 m/s) and FIES (~10 m/s) over ~1200 days. Their data detects both b and c.
  

The stellar companion detected by Ciceri et al. appears to be the same as the one detected by Quinn et al., as they have equal photometric properties despite being detected at different separations.

Finally, the detection of visible star-planet interactions from the brightening of the star after planetary periastron is very interesting, particularly as its seems to dominate all detectable magnetics of the star.

Good call, merged.

System is now designated Kepler-432. Tread title updated.
http://arxiv.org/abs/1410.2999v2