2020A&A...641A..69B


C.D.S. - SIMBAD4 rel 1.7 - 2020.11.28CET20:44:37

2020A&A...641A..69B - Astronomy and Astrophysics, volume 641A, 69-69 (2020/9-1)

The CARMENES search for exoplanets around M dwarfs. Convective shift and starspot constraints from chromatic radial velocities.

BAROCH D., MORALES J.C., RIBAS I., HERRERO E., ROSICH A., PERGER M., ANGLADA-ESCUDE G., REINERS A., CABALLERO J.A., QUIRRENBACH A., AMADO P.J., JEFFERS S.V., CIFUENTES C., PASSEGGER V.M., SCHWEITZER A., LAFARGA M., BAUER F.F., BEJAR V.J.S., COLOME J., CORTES-CONTRERAS M., DREIZLER S., GALADI-ENRIQUEZ D., HATZES A.P., HENNING T., KAMINSKI A., KURSTER M., MONTES D., RODRIGUEZ-LOPEZ C. and ZECHMEISTER M.

Abstract (from CDS):


Context. Variability caused by stellar activity represents a challenge to the discovery and characterization of terrestrial exoplanets and complicates the interpretation of atmospheric planetary signals.
Aims. We aim to use a detailed modeling tool to reproduce the effect of active regions on radial velocity measurements, which aids the identification of the key parameters that have an impact on the induced variability.
Methods. We analyzed the effect of stellar activity on radial velocities as a function of wavelength by simulating the impact of the properties of spots, shifts induced by convective motions, and rotation. We focused our modeling effort on the active star YZ CMi (GJ 285), which was photometrically and spectroscopically monitored with CARMENES and the Telescopi Joan Oro.
Results. We demonstrate that radial velocity curves at different wavelengths yield determinations of key properties of active regions, including spot-filling factor, temperature contrast, and location, thus solving the degeneracy between them. Most notably, our model is also sensitive to convective motions. Results indicate a reduced convective shift for M dwarfs when compared to solar-type stars (in agreement with theoretical extrapolations) and points to a small global convective redshift instead of blueshift .
Conclusions. Using a novel approach based on simultaneous chromatic radial velocities and light curves, we can set strong constraints on stellar activity, including an elusive parameter such as the net convective motion effect.

Abstract Copyright: © ESO 2020

Journal keyword(s): convection - stars: late-type - starspots - stars: activity - techniques: radial velocities

Simbad objects: 3

goto Full paper

goto View the reference in ADS

Number of rows : 3

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 V* YZ CMi Er* 07 44 40.1726285952 +03 33 08.877830321 13.761 12.831 11.225 9.958 8.263 M4.0Ve 790 0
2 NAME beta Pic Moving Group MGr 14 30 -42.0           ~ 582 0
3 NAME Barnard's star BY* 17 57 48.4997994034 +04 41 36.111354228 12.497 11.24 9.511 8.298 6.741 M4V 672 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2020A&A...641A..69B and select 'bookmark this link' or equivalent in the popup menu


2020.11.28-20:44:37

© Université de Strasbourg/CNRS

    • Contact