Kepler-91b Confirmed Through Radial Velocity Detection

Radial velocity confirmation of Kepler-91 b. Additional evidence of its planetary nature using the Calar Alto/CAFE instrument

Authors:

Lillo-Box et al

Abstract:

The object transiting the star Kepler-91 was recently assessed as being of planetary nature. The confirmation was achieved by analysing the light-curve modulations observed in the Kepler data. However, quasi-simultaneous studies claimed a self-luminous nature for this object, thus rejecting it as a planet. In this work, we apply an {independent} approach to confirm the planetary mass of Kepler-91b by using multi-epoch high-resolution spectroscopy obtained with the Calar Alto Fiber-fed Echelle spectrograph (CAFE). We obtain the physical and orbital parameters with the radial velocity technique. In particular, we derive a value of 1.09±0.20MJup for the mass of Kepler-91b, in excellent agreement with our previous estimate that was based on the orbital brightness modulation.