Haywood, Raphaëlle D.Raphaëlle D.HaywoodVanderburg, AndrewAndrewVanderburgMortier, AnneliesAnneliesMortierGiles, Helen A. C.Helen A. C.GilesLópez-Morales, MercedesMercedesLópez-MoralesLopez, Eric D.Eric D.LopezMalavolta, LucaLucaMalavoltaCharbonneau, DavidDavidCharbonneauCollier Cameron, AndrewAndrewCollier CameronCoughlin, Jeffrey L.Jeffrey L.CoughlinDressing, Courtney D.Courtney D.DressingNava, ChantanelleChantanelleNavaLatham, David W.David W.LathamDumusque, XavierXavierDumusqueLovis, ChristopheChristopheLovisMOLINARI, Emilio CarloEmilio CarloMOLINARIPepe, FrancescoFrancescoPepeSOZZETTI, AlessandroAlessandroSOZZETTIUdry, StéphaneStéphaneUdryBouchy, FrançoisFrançoisBouchyJohnson, John A.John A.JohnsonMayor, MichelMichelMayorMICELA, GiuseppinaGiuseppinaMICELAPhillips, DavidDavidPhillipsPiotto, GiampaoloGiampaoloPiottoRice, KenKenRiceSasselov, DimitarDimitarSasselovSégransan, DamienDamienSégransanWatson, ChrisChrisWatsonAFFER, LauraLauraAFFERBONOMO, ALDO STEFANOALDO STEFANOBONOMOBuchhave, Lars A.Lars A.BuchhaveCiardi, David R.David R.CiardiFiorenzano, Aldo F.Aldo F.FiorenzanoHARUTYUNYAN, AVETAVETHARUTYUNYAN2020-10-282020-10-2820180004-6256http://hdl.handle.net/20.500.12386/28064We present the confirmation of a small, moderately irradiated (F = 155 ± 7 F <SUB>⊕</SUB>) 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 <SUB>⊕</SUB>. 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{+/- }<SUB>2.8</SUB><SUP>3.1</SUP> {M}<SUB>\oplus </SUB> via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655b falls 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.STAMPAenArticle10.3847/1538-3881/aab8f32-s2.0-85047351276000430794900002https://iopscience.iop.org/article/10.3847/1538-3881/aab8f32018AJ....155..203HFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_2 Planetary systems sciences