Bibcode
Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.; Toledo-Padrón, B.; Perger, M.; Ribas, I.; Affer, L.; Micela, G.; Damasso, M.; Maldonado, J.; González-Alvarez, E.; Leto, G.; Pagano, I.; Scandariato, G.; Sozzetti, A.; Lanza, A. F.; Malavolta, L.; Claudi, R.; Cosentino, R.; Desidera, S.; Giacobbe, P.; Maggio, A.; Rainer, M.; Esposito, M.; Benatti, S.; Pedani, M.; Morales, J. C.; Herrero, E.; Lafarga, M.; Rosich, A.; Pinamonti, M.
Bibliographical reference
Astronomy and Astrophysics, Volume 612, id.A89, 17 pp.
Advertised on:
5
2018
Journal
Citations
62
Refereed citations
58
Description
We aim to investigate the presence of signatures of magnetic cycles and
rotation on a sample of 71 early M-dwarfs from the HADES RV programme
using high-resolution time-series spectroscopy of the Ca II H&K and
Hα chromospheric activity indicators, the radial velocity series,
the parameters of the cross correlation function and the V -band
photometry. We used mainly HARPS-N spectra, acquired over 4 yr, and add
HARPS spectra from the public ESO database and ASAS photometry
light-curves as support data, extending the baseline of the observations
of some stars up to 12 yr. We provide log10(R'HK)
measurements for all the stars in the sample, cycle length measurements
for 13 stars, rotation periods for 33 stars and we are able to measure
the semi-amplitude of the radial velocity signal induced by rotation in
16 stars. We complement our work with previous results and confirm and
refine the previously reported relationships between the mean level of
chromospheric emission, measured by the
log10(R'HK), with the rotation period, and with
the measured semi-amplitude of the activity induced radial velocity
signal for early M-dwarfs. We searched for a possible relation between
the measured rotation periods and the lengths of the magnetic cycle,
finding a weak correlation between both quantities. Using previous v sin
i measurements we estimated the inclinations of the star's poles to the
line of sight for all the stars in the sample, and estimate the range of
masses of the planets GJ 3998 b and c (2.5-4.9 and 6.3-12.5
M⊕), GJ 625 b (2.82 M⊕), GJ 3942 b
(7.1-10.0 M⊕) and GJ 15A b (3.1-3.3
M⊕), assuming their orbits are coplanar with the
stellar rotation.
Based on: observations made with the Italian Telescopio Nazionale
Galileo (TNG), operated on the island of La Palma by the INAF -
Fundación Galileo Galilei at the Roche de Los Muchachos
Observatory of the Instituto de Astrofísica de Canarias (IAC);
observations made with the HARPS instrument on the ESO 3.6-m telescope
at La Silla Observatory (Chile).