2022A&A...663A..27J


Query : 2022A&A...663A..27J

2022A&A...663A..27J - Astronomy and Astrophysics, volume 663A, 27-27 (2022/7-1)

The CARMENES search for exoplanets around M dwarfs. Benchmarking the impact of activity in high-precision radial velocity measurements.

JEFFERS S.V., BARNES J.R., SCHOFER P., QUIRRENBACH A., ZECHMEISTER M., AMADO P.J., CABALLERO J.A., FERNANDEZ M., RODRIGUEZ E., RIBAS I., REINERS A., CARDONA GUILLEN C., CIFUENTES C., CZESLA S., HATZES A.P., KURSTER M., MONTES D., MORALES J.C., PEDRAZ S. and SADEGI S.

Abstract (from CDS):


Context. Current exoplanet surveys using the radial velocity (RV) technique are targeting M dwarfs because any habitable zone terrestrial-mass planets will induce a high RV and orbit on shorter periods than for more massive stars. One of the main caveats is that M dwarfs show a wide range of activity levels from inactive to very active, which can induce an asymmetry in the line profiles and, consequently, a spurious RV measurement.
Aims. We aim to benchmark the impact of stellar activity on high-precision RV measurements using regular-cadence CARMENES visible and near-infrared observations of the active M3.5 dwarf EV Lac.
Methods. We used the newly developed technique of low-resolution Doppler imaging to determine the centre-of-light, or spot-induced RV component, for eight observational epochs.
Results. We confirm a statistically significant and strong correlation between the independently measured centre-of-light and the chromatic index, which is a measure of the amplitude variation with wavelength of the RVs. We also find circular "closed-loop" relations of several activity indices with RV for a subset of data that covers only several rotation periods. We also investigate the implications of large phase gaps in the periodograms of activity indicators. Finally, by removing the spot-induced RV component we improve the planet-mass sensitivity by a factor of at least three.
Conclusions. We conclude that for active M stars, a regular-cadence observing strategy is the most efficient way to identify and eliminate sources of correlated noise.

Abstract Copyright: © S. V. Jeffers et al. 2022

Journal keyword(s): stars: activity - stars: individual: EV Lac - stars: low-mass - starspots - techniques: radial velocities - stars: magnetic field

Simbad objects: 14

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Number of rows : 14
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 HD 285968 PM* 04 42 55.7750207949 +18 57 29.395947044 12.668 11.49 9.951 8.931 7.702 M2.5V 335 2
2 BD+49 1280 PM* 04 58 50.5747640328 +49 50 57.433739964   11.6   9.373   M0.0V 89 0
3 V* YZ CMi Er* 07 44 40.1723046464 +03 33 08.875227574 13.761 12.831 11.225 9.958 8.263 M4.0Ve 882 0
4 Wolf 359 Er* 10 56 28.9208702274 +07 00 53.003285286 16.706 15.541 13.507 11.684 9.507 dM6 719 0
5 * 61 UMa PM* 11 41 03.0162706212 +34 12 05.881605449 6.31 6.08 5.34 4.73 4.38 G8V 612 0
6 BD+36 2219 LM* 11 51 07.3365505565 +35 16 19.248218463   11.30 9.802 9.420 7.64 M1.5V 177 0
7 * tau Boo Ro* 13 47 15.7381720026 +17 27 24.809555600 5.02 4.98 4.49 4.09 3.85 F7IV-V 986 1
8 NAME Proxima Centauri Er* 14 29 42.9461331854 -62 40 46.164680672 14.21 12.95 11.13 9.45 7.41 M5.5Ve 1296 0
9 CD-46 11540 LM* 17 28 39.9455781571 -46 53 42.688095874 12.177 10.973 9.407 8.337 7.006 M3V 252 1
10 NAME Barnard's star BY* 17 57 48.4984700685 +04 41 36.113879676 12.497 11.24 9.511 8.298 6.741 M4V 810 2
11 CD-23 14742 Er* 18 49 49.3637762005 -23 50 10.447375350 13.528 12.19 10.43 10.23 7.703 M3.5Ve 377 0
12 HD 197481 BY* 20 45 09.5324974119 -31 20 27.237889841   10.05 8.627 9.078 6.593 M1VeBa1 1150 0
13 V* EV Lac Er* 22 46 49.7312610268 +44 20 02.374381562   11.85 10.26 9.89   M4.0Ve 900 2
14 HD 217987 PM* 23 05 52.0357857091 -35 51 11.055185039   8.83 7.39     M2V 272 0

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