Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune
Artikel i vetenskaplig tidskrift, 2019
We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6 ± 3.0 m/s, which matches the transit ephemeris, and translates to a planet mass of 21.8 ± 6.2 M⊕. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, 2.04-0.6+0.66 g/cm^-3, implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of 10^11-10^12 g/s due to the high level of radiation it receives from its host star.
techniques: radial velocities
planets and satellites: individual: K2-100b
Astrophysics - Earth and Planetary Astrophysics
Astrophysics - Solar and Stellar Astrophysics