J/AJ/165/74 HIRES / HARPS-N radial velocities of Kepler-102 (Brinkman+, 2023)
Kepler-102: Masses and Compositions for a Super-Earth and Sub-Neptune Orbiting
an Active Star.
Brinkman C.L., Cadman J., Weiss L., Gaidos E., Rice K., Huber D.,
Claytor Z.R., Bonomo A.S., Buchhave L.A., Cameron A.C., Cosentino R.,
Dumusque X., Martinez Fiorenzano A.F., Ghedina A., Harutyunyan A.,
Howard A., Isaacson H., Latham D.W., Lopez-Morales M., Malavolta L.,
Micela G., Molinari E., Pepe F., Philips D.F., Poretti E., Sozzetti A.,
Udry S.
<Astron. J., 165, 74 (2023)>
=2023AJ....165...74B 2023AJ....165...74B
ADC_Keywords: Exoplanets; Stars, high-velocity; Spectra, optical;
Radial velocities
Keywords: Exoplanets ; Super Earths ; Mini Neptunes ; Extrasolar rocky
planets ; Gaussian Processes regression ; Radial velocity
Abstract:
Radial velocity (RVel) measurements of transiting multiplanet systems
allow us to understand the densities and compositions of planets
unlike those in the solar system. Kepler-102, which consists of five
tightly packed transiting planets, is a particularly interesting
system since it includes a super-Earth (Kepler-102d) and a
sub-Neptune-sized planet (Kepler-102e) for which masses can be
measured using RVs. Previous work found a high density for
Kepler-102d, suggesting a composition similar to that of Mercury,
while Kepler-102e was found to have a density typical of sub-Neptune
size planets; however, Kepler-102 is an active star, which can
interfere with RVel mass measurements. To better measure the mass of
these two planets, we obtained 111 new RVels using Keck/HIRES and
Telescopio Nazionale Galileo/HARPS-N and modeled Kepler-102's activity
using quasiperiodic Gaussian process regression. For Kepler-102d, we
report a mass upper limit Md<5.3M⊕ (95% confidence), a best-fit
mass Md=2.5±1.4M⊕, and a density ρd=5.6±3.2g/cm3,
which is consistent with a rocky composition similar in density to the
Earth. For Kepler-102e we report a mass Me=4.7±1.7M⊕ and a
density ρe=1.8±0.7g/cm3. These measurements suggest that
Kepler-102e has a rocky core with a thick gaseous envelope comprising
2%-4% of the planet mass and 16%-50% of its radius. Our study is yet
another demonstration that accounting for stellar activity in stars
with clear rotation signals can yield more accurate planet masses,
enabling a more realistic interpretation of planet interiors.
Description:
We make use of 72 radial velocities from the High Resolution Echelle
Spectrometer (HIRES) on the 10m Keck I telescope.
We obtained a total of 78 radial velocities for Kepler-102 using the
High Accuracy Radial velocity Planet Searcher North (HARPS-N)
spectrograph installed on the 3.6m Telescopio Nazionale Galileo (TNG)
at the Observatorio Roque de Los Muchachos in La Palma, Spain.
Objects:
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RA (2000) DE Designation(s)
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18 45 55.85 +47 12 28.8 Kepler-102 = 2MASS J18455585+4712289
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 59 146 Radial velocity table
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See also:
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/ApJ/776/67 : Rotational tracks (van Saders+, 2013)
J/ApJ/789/154 : Kepler-10 RV measurements by HARPS-N (Dumusque+, 2014)
J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)
J/ApJ/800/135 : HARPS-N radial velocities of KOI-69 (Dressing+, 2015)
J/A+A/588/A118 : Pr0211 RVs, photometry and activity indexes (Malavolta+, 2016)
J/ApJ/822/86 : False positive probabilities Q1-Q17 DR24 KOIs (Morton+, 2016)
J/AJ/154/109 : California-Kepler Survey. III. Planet radii (Fulton+, 2017)
J/ApJ/866/99 : Radii of KIC stars & planets using Gaia DR2 (Berger+, 2018)
J/AJ/156/264 : California-Kepler Survey VII Planet radius gap (Fulton+, 2018)
J/AJ/155/107 : HARPS-N obs. of K2-141 planetary system (Malavolta+, 2018)
J/other/RAA/19.41 : TTVs & linear ephemerides Kepler exoplanets (Gajdos+, 2019)
J/AJ/157/116 : RVel of K2-291 with HIRES & HARPS-N (Kosiarek+, 2019)
J/AJ/161/36 : 117 exoplanets habitable zone with Kepler DR25 (Bryson+, 2021)
J/A+A/648/A103 : Thorium line list (Dumusque+, 2021)
J/AJ/162/55 : 65 Transit-timing variation planets properties (Yee+, 2021)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD [2455312/2459059] Barycentric Julian Date at TDB
15- 20 F6.2 m/s RVel [-13.4/9.1] Radial Velocity
22- 25 F4.2 m/s e_RVel [1/8] Uncertainty in RVel
27- 30 F4.2 --- SI [0.27/0.55]? Activity Indicator, S-index for HIRES
32- 38 F7.2 m/s FWHM [6180/7783]? Activity Indicator, FWHM for HARPS-N
40- 59 A20 --- Inst Instrument used; HARPS or HIRE (1)
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Note (1): The first 35 Keck/HIRES RVs are published in
Marcy+, 2014, J/ApJS/210/20, and the remainder are to be published in
Weiss+, (in prep) and were obtained in private communication.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 01-Jun-2023