An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope
Abstract
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{+/- }2.83.1 {M}\oplus 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.
- Publication:
-
The Astronomical Journal
- Pub Date:
- May 2018
- DOI:
- 10.3847/1538-3881/aab8f3
- arXiv:
- arXiv:1803.08820
- Bibcode:
- 2018AJ....155..203H
- Keywords:
-
- stars: individual: Kepler-1655;
- KOI-280;
- KIC 4141376;
- 2MASS J19064546+3912428;
- planets and satellites: detection;
- planets and satellites: gaseous planets;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 21 pages, 14 figures, 4 tables