An accurate mass determination for Kepler-1655b, a moderately-irradiated world with a significant volatile envelope

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 TNG/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0±^3.1_2.8 M⊕ 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.

Citation

Haywood , R D , Vanderburg , A , Mortier , A , Giles , H A C , Lopez-Morales , M , Lopez , E D , Malavolta , L , Charbonneau , D , Cameron , A C , Coughlin , J L , Dressing , C D , Nava , C , Latham , D W , Dumusque , X , Lovis , C , Molinari , E , Pepe , F , Sozzetti , A , Udry , S , Bouchy , F , Johnson , J A , Mayor , M , Micela , G , Phillips , D , Piotto , G , Rice , K , Sasselov , D , Segransan , D , Watson , C , Affer , L , Bonomo , A S , Buchhave , L A , Ciardi , D R , Fiorenzano , A F & Harutyunyan , A 2018 , ' An accurate mass determination for Kepler-1655b, a moderately-irradiated world with a significant volatile envelope ' , Astronomical Journal , vol. 155 , no. 5 , 203 . https://doi.org/10.3847/1538-3881/aab8f3

Publication

Astronomical Journal

Status

Peer reviewed

DOI

https://doi.org/10.3847/1538-3881/aab8f3

ISSN

0004-6256

Type

Journal article

Rights

© 2018, American Astronomical Society. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at http://iopscience.iop.org/journal/1538-3881

Description

Funding: A.C.C. acknowledges support from STFC consolidated grant number ST/M001296/1. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant Agreement No. 313014 (ETAEARTH).

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