J/AJ/157/116 Radial velocities of K2-291 with HIRES & HARPS-N (Kosiarek+, 2019)
K2-291b: a rocky super-Earth in a 2.2 day orbit.
Kosiarek M.R., Blunt S., Lopez-Morales M., Crossfield I.J.M., Sinukoff E.,
Petigura E.A., Gonzales E.J., Poretti E., Malavolta L., Howard A.W.,
Isaacson H., Haywood R.D., Ciardi D.R., Bristow M., Cameron A.C.,
Charbonneau D., Dressing C.D., Figueira P., Fulton B.J., Hardee B.J.,
Hirsch L.A., Latham D.W., Mortier A., Nava C., Schlieder J.E.,
Vanderburg A., Weiss L., Bonomo A.S., Bouchy F., Buchhave L.A., Coffinet A.,
Damasso M., Dumusque X., Lovis C., Mayor M., Micela G., Molinari E.,
Pepe F., Phillips D., Piotto G., Rice K., Sasselov D., Segransan D.,
Sozzetti A., Udry S., Watson C.
<Astron. J., 157, 116 (2019)>
=2019AJ....157..116K 2019AJ....157..116K (SIMBAD/NED BibCode)
ADC_Keywords: Radial velocities ; Exoplanets ; Stars, double and multiple
Keywords: planets and satellites: composition -
planets and satellites: detection - techniques: radial velocities
Abstract:
K2-291 is a solar-type star with a radius of R*=0.899±0.034 R☉
and mass of M*=0.934±0.038 M☉. From the K2 C13 data, we found
one super-Earth planet (Rp=1.589-0.072+0.095 R⊕) transiting
this star on a short period orbit (P=2.225177-6.8e-5+6.6e-5 days). We
followed this system up with adaptive-optic imaging and spectroscopy
to derive stellar parameters, search for stellar companions, and determine
a planet mass. From our 75 radial velocity measurements using High
Resolution Echelle Spectrometer on Keck I and High Accuracy Radial velocity
Planet Searcher in the northern hemisphere on Telescopio Nazionale Galileo,
we constrained the mass of K2-291 b to Mp=6.49±1.16 M⊕. We
found it necessary to model correlated stellar activity radial velocity
signals with a Gaussian process (GP) in order to more accurately model
the effect of stellar noise on our data; the addition of the GP also
improved the precision of this mass measurement. With a bulk density of
ρ=8.84-2.03+2.50 g/cm3, the planet is consistent with an
Earth-like rock/iron composition and no substantial gaseous envelope.
Such an envelope, if it existed in the past, was likely eroded away by
photoevaporation during the first billion years of the star's lifetime.
Description:
We collected 75 radial velocity measurements of K2-291 (Table 2) with
the High Resolution Echelle Spectrometer (HIRES; Vogt et al.
1994SPIE.2198..362V 1994SPIE.2198..362V) on the Keck I Telescope on Maunakea and the High
Accuracy Radial velocity Planet Searcher in the Northern hemisphere
(HARPS-N; Cosentino et al. 2012SPIE.8446E..1VC) on the Telescopio
Nazionale Galileo in La Palma (Table 2). HARPS-N is an updated version
of HARPS at the European Southern Observatory (ESO) 3.6 m (Mayor et al.
2003Msngr.114...20M 2003Msngr.114...20M). We obtained 50 measurements with HIRES between
2017 August and 2018 February. We obtained 25 measurements with
HARPS-N between 2017 November and 2018 March as part of the HARPS-N
Collaboration's Guaranteed Time Observations (GTO) program.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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05 05 46.99 +21 32 55.0 K2-291 = HD 285181 (Per=2.225177)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 42 75 Radial velocities
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)
J/AJ/157/52 : Radial velocity observations in super-Earth systems
(Bryan+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date at UTC
15- 22 F8.2 m/s RV [-16.88/25150.7] Radial velocity
24- 27 F4.2 m/s e_RV [0.98/4.73] Uncertainty in RV
29- 34 F6.4 --- SHK [0.2131/0.2859] Ca II H&K line emission indicator
36- 42 A7 --- Inst Instrument (1)
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Note (1): Instrument as follows:
HARPS-N = High Accuracy Radial velocity Planet Searcher in the Northern
hemisphere, Telescopio Nazionale Galileo in La Palma;
HIRES = High Resolution Echelle Spectrometer (HIRES); Keck I.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 07-Jun-2019