Volume 653, September 2021
|Number of page(s)||27|
|Section||Stellar structure and evolution|
|Published online||07 September 2021|
The CARMENES search for exoplanets around M dwarfs
Spectroscopic orbits of nine M-dwarf multiple systems, including two triples, two brown dwarf candidates, and one close M-dwarf–white dwarf binary
Institut de Ciències de l’Espai (ICE, CSIC), Campus UAB, c/ Can Magrans s/n, 08193 Bellaterra, Barcelona, Spain
2 Institut d’Estudis Espacials de Catalunya (IEEC), c/ Gran Capità 2–4, 08034 Barcelona, Spain
3 Instituto de Astrofísica de Canarias, Vía Láctea s/n, 38205 La Laguna, Tenerife, Spain
4 Departamento de Astrofísica, Universidad de La Laguna, 38026 La Laguna, Tenerife, Spain
5 Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany
6 Institut für Astrophysik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
7 Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
8 Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, 18008 Granada, Spain
9 Spanish Virtual Observatory, Spain
10 Centro Astronónomico Hispano Alemán, Observatorio de Calar Alto, Sierra de los Filabres, 04550 Gérgal, Spain
11 Thüringer Landesstenwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
12 Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
13 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
14 Departamento de Física de la Tierra y Astrofísica and IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos de la UCM), Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
15 Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
16 Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
17 Department of Physics, Ariel University, Ariel 40700, Israel
Accepted: 29 May 2021
Context. M dwarfs are ideal targets for the search of Earth-size planets in the habitable zone using the radial velocity method, and are attracting the attention of many ongoing surveys. One of the expected results of these surveys is that new multiple-star systems have also been found. This is the case also for the CARMENES survey, thanks to which nine new double-line spectroscopic binary systems have already been announced.
Aims. Throughout the five years of the survey the accumulation of new observations has resulted in the detection of several new multiple-stellar systems with long periods and low radial-velocity amplitudes. Here we newly characterise the spectroscopic orbits and constrain the masses of eight systems and update the properties of a system that we had reported earlier.
Methods. We derived the radial velocities of the stars using two-dimensional cross-correlation techniques and template matching. The measurements were modelled to determine the orbital parameters of the systems. We combined CARMENES spectroscopic observations with archival high-resolution spectra from other instruments to increase the time span of the observations and improve our analysis. When available, we also added archival photometric, astrometric, and adaptive optics imaging data to constrain the rotation periods and absolute masses of the components.
Results. We determined the spectroscopic orbits of nine multiple systems, eight of which are presented for the first time. The sample is composed of five single-line binaries, two double-line binaries, and two triple-line spectroscopic triple systems. The companions of two of the single-line binaries, GJ 3626 and GJ 912, have minimum masses below the stellar boundary, and thus could be brown dwarfs. We found a new white dwarf in a close binary orbit around the M star GJ 207.1, located at a distance of 15.79 pc. From a global fit to radial velocities and astrometric measurements, we were able to determine the absolute masses of the components of GJ 282 C, which is one of the youngest systems with measured dynamical masses.
Key words: stars: low-mass / brown dwarfs / white dwarfs / binaries: spectroscopic / astrometry
© ESO 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.