J/AJ/157/100 Radial velocities and bisector spans for K2-287 (Jordan+, 2019)
K2-287 b: an eccentric warm Saturn transiting a G-dwarf.
Jordan A., Brahm R., Espinoza N., Cortes C., Diaz M., Drass H., Henning T.,
Jenkins J.S., Jones M.I., Rabus M., Rojas F., Sarkis P., Vuckovic M.,
Zapata A., Soto M.G., Bakos G.A., Bayliss D., Bhatti W., Csubry Z.,
Lachaume R., Moraga V., Pantoja B., Osip D., Shporer A., Suc V., Vasquez S.
<Astron. J., 157, 100-100 (2019)>
=2019AJ....157..100J 2019AJ....157..100J (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, G-type ; Radial velocities ; Exoplanets
Keywords: planetary systems - planets and satellites: detection -
planets and satellites: gaseous planets - stars: individual: K2-287
Abstract:
We report the discovery of K2-287b, a Saturn mass planet orbiting a
G-dwarf with a period of P∼15 days. First uncovered as a candidate using
K2 campaign 15 data, follow-up photometry and spectroscopy were used to
determine a mass MP=0.317±0.026 MJ, radius RP=0.833±0.013 RJ,
period P=14.893291±0.000025 days, and eccentricity e=0.476±0.026.
The host star is a metal-rich V=11.410±0.129 mag G-dwarf for which
we estimate a mass M*=1.056-0.021+0.022 M☉_, radius
R*=1.070±0.010 R☉, metallicity [Fe/H]=0.20±0.05, and
Teff=5673±75 K. This warm eccentric planet with a time-averaged
equilibrium temperature of Teq∼800 K adds to the small sample of giant
planets orbiting nearby stars whose structure is not expected to be
affected by stellar irradiation. Follow-up studies on the K2-287 system
could help constrain theories of planet migration in close-in orbits.
Description:
We obtained 52 R=48000 spectra between March and July of 2018 using
the FEROS spectrograph (Kaufer et al. 1999Msngr..95....8K 1999Msngr..95....8K) mounted on
the 2.2 MPG telescope in the La Silla observatory. Each spectrum achieved
a signal-to-noise ratio of ∼90 per spectral resolution element. The
instrumental drift was determined via comparison with a simultaneous fiber
illuminated with a ThAr+Ne lamp. We additionally obtained 25 R=115000
spectra between March and August of 2018 using the HARPS spectrograph
(Mayor et al. 2003Msngr.114...20M 2003Msngr.114...20M). Typical signal-to-noise ratio for
these spectra ranged between 30 and 50 per spectral resolution element.
Both FEROS and HARPS data were processed with the CERES suite of echelle
pipelines (Brahm et al. 2017PASP..129c4002B 2017PASP..129c4002B), which produce radial
velocities and bisector spans in addition to reduced spectra.
Objects:
--------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
--------------------------------------------------------------------
15 32 17.85 -22 21 29.8 K2-287 = EPIC 249451861 (P=14.893291)
--------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 47 77 Relative radial velocities and bisector spans
for K2-287
--------------------------------------------------------------------------------
See also:
J/AJ/154/207 : K2 planetary systems orbiting low-mass stars (Dressing+, 2017)
J/ApJ/836/167 : K2 planetary syst. around low-mass stars. I. (Dressing+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.7 d BJD [58168.8/58333.6] Barycentric Julian Date
(BJD-2400000)
15- 21 F7.4 m/s RV [32.8463/33.0158] Radial velocity
23- 28 F6.4 m/s e_RV [0.0029/0.0095] Uncertainty in RV
30- 35 F6.3 m/s BIS [-0.1/0.025] Bisector span
37- 41 F5.3 m/s e_BIS [0.004/0.015] Uncertainty in BIS
43- 47 A5 --- Inst Instrument (FEROS or HARPS)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 04-Jun-2019