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. =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 M_P_=0.317+/-0.026 M_J_, radius R_P_=0.833+/-0.013 R_J_, 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_{sun}__, radius R_*_=1.070+/-0.010 R_{sun}_, metallicity [Fe/H]=0.20+/-0.05, and T_eff_=5673+/-75 K. This warm eccentric planet with a time-averaged equilibrium temperature of T_eq_~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) 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). 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), 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