J/A+A/643/A112 CARMENES VIS RVs of 3 M dwarfs (Stock+, 2020)
The CARMENES search for exoplanets around M dwarfs.
Three temperate-to-warm super-Earths.
Stock S., Nagel E., Kemmer J., Passegger V.M., Reffert S., Quirrenbach A.,
Caballero J.A., Czesla S., Bejar V.J.S., Cardona C., Diez-Alonso E.,
Herrero E., Lalitha S., Schlecker M., Tal-Or L., Rodriguez E.,
Rodriguez-Lopez C., Ribas I., Reiners A., Amado P.J., Bauer F.F.,
Bluhm P., Cortes-Contreras M., Gonzalez-Cuesta L., Dreizler S., Hatzes A.P.,
Henning T., Jeffers S.V., Kaminski A., Kuerster M., Lafarga M.,
Lopez-Gonzalez M.J., Montes D., Morales J.C., Pedraz S., Schoefer P.,
Schweitzer A., Trifonov T., Zapatero Osorio M.R., Zechmeister M.
<Astron. Astrophys. 643, A112 (2020)>
=2020A&A...643A.112S 2020A&A...643A.112S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, M-type ; Exoplanets ;
Radial velocities ; Optical
Keywords: planetary systems - techniques: radial velocities -
stars: individual: GJ 251 - stars: individual: HD 238090 -
stars: individual: Lalande 21185 - stars: late-type
Abstract:
We announce the discovery of two planets orbiting the M dwarfs GJ 251
(0.360±0.015M☉) and HD 238090 (0.578±0.021M☉) based on
CARMENES radial velocity (RV) data. In addition, we independently
confirm with CARMENES data the existence of Lalande 21185 b, a planet
that has recently been discovered with the SOPHIE spectrograph. All
three planets belong to the class of warm or temperate super-Earths
and share similar properties. The orbital periods are 14.24d, 13.67d,
and 12.95d and the minimum masses are 4.0±0.4M☉,
6.9±0.9M☉, and 2.7±0.3M☉ for GJ 251 b, HD 238090 b,
and Lalande 21185 b, respectively. Based on the orbital and stellar
properties, we estimate equilibrium temperatures of 351.0±1.4K for
GJ 251 b, 469.6±2.6K for HD 238090 b, and 370.1±6.8K for Lalande
21185 b. For the latter we resolve the daily aliases that were present
in the SOPHIE data and that hindered an unambiguous determination of
the orbital period. We find no significant signals in any of our
spectral activity indicators at the planetary periods. The RV
observations were accompanied by contemporaneous photometric
observations. We derive stellar rotation periods of 122.1±2.2d and
96.7±3.7d for GJ 251 and HD 238090, respectively. The RV data of all
three stars exhibit significant signals at the rotational period or
its first harmonic. For GJ 251 and Lalande 21185, we also find
long-period signals around 600d, and 2900d, respectively, which we
tentatively attribute to long-term magnetic cycles. We apply a
Bayesian approach to carefully model the Keplerian signals
simultaneously with the stellar activity using Gaussian process
regression models and extensively search for additional significant
planetary signals hidden behind the stellar activity. Current planet
formation theories suggest that the three systems represent a common
architecture, consistent with formation following the core accretion
paradigm.
Description:
We acquired spectra with CARMENES (Quirrenbach et al., 2014, in Proc.
SPIE, Vol. 9147, Ground-based and Airborne Instrumentation for
Astronomy V, 91471F), a high-resolution precise echelle spectrograph
mounted at the 3.5m telescope at the Calar Alto Observatory in Spain.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s) (Prot)
------------------------------------------------------------
06 54 48.96 +33 16 05.4 GJ 251 = HD 265866 (122.1)
12 12 20.86 +54 29 08.7 HD 238090 = HIP 59514 ( 96.7)
11 03 20.19 +35 58 11.6 Lalande 21185 = HD 95735 ( 56.15)
------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tabled1.dat 68 212 CARMENES VIS RVs and some activity indicators
of GJ251
tabled2.dat 68 108 CARMENES VIS RVs and some activity indicators
of HD 238090
tabled3.dat 68 321 CARMENES VIS RVs and some activity indicators
of Lalande 21185
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d BJD Barycentric Julian date
15- 20 F6.2 m/s RV Radial velocity
22- 26 F5.2 m/s e_RV Radial velocity uncertainty
28- 34 F7.2 m/s CRX Chromatic Index
36- 41 F6.2 m/s e_CRX Chromatic Index uncertainty
43- 49 F7.2 --- dLW Differential line width
51- 55 F5.2 --- e_dLW Differential line width uncertainty
57- 62 F6.3 --- Ha Halpha index
64- 68 F5.3 --- e_Ha Halpha index uncertainty
--------------------------------------------------------------------------------
Acknowledgements:
Stephan Stock, sstock(at)lsw.uni-heidelberg.de
(End) Patricia Vannier [CDS] 05-Oct-2020