The Kepler-454 System: A Small, Not-rocky Inner Planet, a Jovian World, and a Distant Companion
Journal
Date Issued
2016
Author(s)
Gettel, Sara
•
Charbonneau, David
•
Dressing, Courtney D.
•
Buchhave, Lars A.
•
Dumusque, Xavier
•
Vanderburg, Andrew
•
•
•
Pepe, Francesco
•
Collier Cameron, Andrew
•
Latham, David W.
•
Udry, Stéphane
•
Marcy, Geoffrey W.
•
Isaacson, Howard
•
Howard, Andrew W.
•
Davies, Guy R.
•
Silva Aguirre, Victor
•
Kjeldsen, Hans
•
Bedding, Timothy R.
•
Lopez, Eric
•
•
•
Figueira, Pedro
•
Fiorenzano, Aldo F. M.
•
•
Johnson, John Asher
•
Lopez-Morales, Mercedes
•
Lovis, Christophe
•
Mayor, Michel
•
•
•
Motalebi, Fatemeh
•
Phillips, David F.
•
Piotto, Giampaolo
•
Queloz, Didier
•
Rice, Ken
•
Sasselov, Dimitar
•
Ségransan, Damien
•
•
Watson, Chris
•
Basu, Sarbani
•
Campante, Tiago L.
•
Christensen-Dalsgaard, Jørgen
•
Kawaler, Steven D.
•
Metcalfe, Travis S.
•
Handberg, Rasmus
•
Lund, Mikkel N.
•
Lundkvist, Mia S.
•
Huber, Daniel
•
Chaplin, William J.
Abstract
Kepler-454 (KOI-273) is a relatively bright (V = 11.69 mag), Sun-like star that hosts a transiting planet candidate in a 10.6 day orbit. From spectroscopy, we estimate the stellar temperature to be 5687 ± 50 K, its metallicity to be [m/H] = 0.32 ± 0.08, and the projected rotational velocity to be v sin I < 2.4 km s-1. We combine these values with a study of the asteroseismic frequencies from short cadence Kepler data to estimate the stellar mass to be {1.028}-0.03+0.04{M}☉ , the radius to be 1.066 ± 0.012 R☉, and the age to be {5.25}-1.39+1.41 Gyr. We estimate the radius of the 10.6 day planet as 2.37 ± 0.13 R⊕. Using 63 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 36 observations made with the HIRES spectrograph at the Keck Observatory, we measure the mass of this planet to be 6.8 ± 1.4 M⊕. We also detect two additional non-transiting companions, a planet with a minimum mass of 4.46 ± 0.12 MJ in a nearly circular 524 day orbit and a massive companion with a period >10 years and mass >12.1 MJ. The 12 exoplanets with radii <2.7 R⊕ and precise mass measurements appear to fall into two populations, with those <1.6 R⊕ following an Earth-like composition curve and larger planets requiring a significant fraction of volatiles. With a density of 2.76 ± 0.73 g cm-3, Kepler-454b lies near the mass transition between these two populations and requires the presence of volatiles and/or H/He gas.
Volume
816
Issue
2
Start page
95
Issn Identifier
0004-637X
Ads BibCode
2016ApJ...816...95G
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
Getteletal_2016.pdf
Description
Pdf editoriale
Size
1.81 MB
Format
Adobe PDF
Checksum (MD5)
8df7275ece48dd4b58560f74bfd0985f