Haywood, Raphaëlle D.Raphaëlle D.HaywoodVanderburg, AndrewAndrewVanderburgMortier, AnneliesAnneliesMortierGiles, Helen A. C.Helen A. C.GilesLópez-Morales, MercedesMercedesLópez-MoralesLopez, Eric D.Eric D.LopezMalavolta, LucaLucaMalavolta0000-0002-6492-2085Charbonneau, DavidDavidCharbonneauCollier Cameron, AndrewAndrewCollier CameronCoughlin, Jeffrey L.Jeffrey L.CoughlinDressing, Courtney D.Courtney D.DressingNava, ChantanelleChantanelleNavaLatham, David W.David W.LathamDumusque, XavierXavierDumusqueLovis, ChristopheChristopheLovisMOLINARI, Emilio CarloEmilio CarloMOLINARI0000-0002-1742-7735Pepe, FrancescoFrancescoPepeSOZZETTI, AlessandroAlessandroSOZZETTI0000-0002-7504-365XUdry, StéphaneStéphaneUdryBouchy, FrançoisFrançoisBouchyJohnson, John A.John A.JohnsonMayor, MichelMichelMayorMICELA, GiuseppinaGiuseppinaMICELA0000-0002-9900-4751Phillips, DavidDavidPhillipsPiotto, GiampaoloGiampaoloPiottoRice, KenKenRiceSasselov, DimitarDimitarSasselovSégransan, DamienDamienSégransanWatson, ChrisChrisWatsonAFFER, LauraLauraAFFER0000-0001-5600-3778BONOMO, ALDO STEFANOALDO STEFANOBONOMO0000-0002-6177-198XBuchhave, 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