Analysis of the exoplanet containing system Kepler 91
arXiv:1507.02060 · doi:10.1007/s10509-015-2564-4
Abstract
We have applied the graphical user interfaced close binary system analysis program WinFitter to an intensive study of Kepler 91 using all the available photometry from the NASA Exoplanet Archive (NEA) at the Caltech website: http://exoplanetarchive.ipac.caltech.edu . Our fitting function for the tidal distortion derives from the relevant Radau equation and includes terms up to the fifth power of the fractional radius. This results in a systematic improvement in the mass ratio estimation over that of Lillo Box et al (2014a) and our derived value for the mass ratio is in close agreement with that inferred from recent high-resolution spectroscopic data. It is clear that the data analysis in terms of simply an eclipsing binary system is compromised by the presence of significant other causes of light variation, in particular non-radial pulsations. We apply a low-frequency filtering procedure to separate out some of this additional light variation. Whilst the derived eccentricity appears then reduced, an eccentric effect remains in the light curve. We consider how this may be maintained in spite of likely frictional effects operating over a long time. There are also indications of the possible effects of Trojan or other period-resonant mass concentrations. Suggestions of a possible secular period variation are briefly discussed.
12 pages, 5 figures
References in corpus (11)
- Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
- Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology
- Retired A Stars and Their Companions: Exoplanets Orbiting Three Intermediate-Mass Subgiants
- Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
- Optical Phase Curves of Kepler Exoplanets
- Kepler-91b: a planet at the end of its life. Planet and giant host star properties via light-curve variations
- Radial Velocity Observations and Light Curve Noise Modeling Confirm That Kepler-91b is a Giant Planet Orbiting a Giant Star
- A High False Positive Rate for Kepler Planetary Candidates of Giant Stars using Asterodensity Profiling
- Radial velocity confirmation of Kepler-91 b. Additional evidence of its planetary nature using the Calar Alto/CAFE instrument
- Analysis of selected Kepler Mission planetary light curves
- Precise Radial Velocity Measurements for Kepler Giants Hosting Planetary Candidates: Kepler-91 and KOI-1894