摘要：We present the confirmation of a small, moderately irradiated (F = 155 ± 7 F⊕) Neptune with a substantial gas envelope in a P=11.8728787±0.0000085 day orbit about a quiet, Sun-like G0V star Kepler-1655. Based on our analysis of the Kepler light curve, we determined Kepler-1655b’s radius to be 2.213±0.082 R⊕. We acquired 95 high-resolution spectra with Telescopio Nazionale Galileo/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0 2.8 M 3.1 Å via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655bfalls on the upper edge of the evaporation valley, in the relatively sparsely occupied transition region between rocky and gas-rich planets. It is therefore part of a population of planets that we should actively seek to characterize further.
关键词：stars: individual (Kepler-1655, KOI-280, KIC 4141376, 2MASS J19064546+3912428);planets and satellites: detection;planets and satellites: gaseous planets
