1 research outputs found
Radial velocity confirmation of K2-100b: A young, highly irradiated, and low-density transiting hot Neptune
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 days. We model the activity-induced
radial velocity variations of the host star with a multi-dimensional Gaussian
Process framework and detect a planetary signal of , which matches the transit ephemeris, and translates to a planet
mass of . 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, , implies that K2-100b
retains a significant volatile envelope. We estimate that the planet is losing
its atmosphere at a rate of due to the high
level of radiation it receives from its host star.O.B. and S.Ai. acknowledge support from
the UK Science and Technology Facilities Council (STFC) under grants
ST/S000488/1 and ST/R004846/1. J.K., S.G. and A.P.H acknowledges support by Deutsche Forschungsgemeinschaft (DFG) grants PA525/18-1 and
PA525/19-1 and HPA 3279/12-1 within the DFG Schwerpunkt SPP 1992,
Exploring the Diversity of Extra-solar Planets. L.M. acknowledges support from PLATO ASI-INAF agreement n.2015-019-R.1-2018. S.Al. acknowledges the support from the Danish Council for Independent Research through the DFF Sapere Aude Starting Grant No. 4181-00487B, and
the Stellar Astrophysics Centre which funding is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). This
work is partly supported by JSPS KAKENHI Grant Numbers JP18H01265,
JP18H05439, 15H02063, and 18H05442 and JST PRESTO Grant Number
JPMJPR1775. M.C.V.F. and C.M.P. gratefully acknowledge the support of
the Swedish National Space Agency (DNR 174/18)