Kepler-1656b: A Dense Sub-Saturn with an Extreme Eccentricity

October 2018 • 2018AJ....156..147B

Authors • Brady, Madison T. • Petigura, Erik A. • Knutson, Heather A. • Sinukoff, Evan • Isaacson, Howard • Hirsch, Lea A. • Fulton, Benjamin J. • Kosiarek, Molly R. • Howard, Andrew W.

Abstract • Kepler-1656b is a 5 {R}_\oplus planet with an orbital period of 32 days initially detected by the prime Kepler mission. We obtained precision radial velocities of Kepler-1656 with Keck/HIRES in order to confirm the planet and to characterize its mass and orbital eccentricity. With a mass of 48 ± 4 {M}_\oplus , Kepler-1656b is more massive than most planets of comparable size. Its high mass implies that a significant fraction, roughly 80%, of the planet’s total mass is in high-density material such as rock/iron, with the remaining mass in a low-density H/He envelope. The planet also has a high eccentricity of 0.84 ± 0.01, the largest measured eccentricity for any planet less than 100 {M}_\oplus . The planet’s high density and high eccentricity may be the result of one or more scattering and merger events during or after the dispersal of the protoplanetary disk.

Links

• PREPRINT http://arxiv.org/abs/1809.08436
• ELECTR https://doi.org/10.3847%2F1538-3881%2Faad773
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2018AJ....156..147B
• PDF https://stacks.iop.org/1538-3881/156/147/pdf
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/147
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2018AJ....156..147B
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2018AJ....156..147B
• DATA https://irsa.ipac.caltech.edu/bibdata/2018/B/2018AJ....156..147B.html