Issue |
A&A
Volume 624, April 2019
|
|
---|---|---|
Article Number | A123 | |
Number of page(s) | 19 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/201935192 | |
Published online | 24 April 2019 |
Gliese 49: activity evolution and detection of a super-Earth
A HADES and CARMENES collaboration★,★★
1
Institut de Ciències de l’Espai (ICE, CSIC),
Campus UAB, Carrer de Can Magrans s/n,
08193 Bellaterra, Spain
e-mail: map@posteo.de
2
Institut d’Estudis Espacials de Catalunya (IEEC),
08034 Barcelona, Spain
3
INAF – Osservatorio Astrofisico di Catania,
via S. Sofia 78,
95123 Catania, Italy
4
INAF – Osservatorio Astronomico di Palermo,
Piazza del Parlamento 1,
90134 Palermo, Italy
5
Centro Astronómico Hispano-Alemán (CAHA). Calar Alto Observatory,
c/ Jesús Durbán Remón 2-2,
04004 Almería, Spain
6
Instituto de Astrofísica de Andalucía (IAA-CSIC),
Glorieta de la Astronomía s/n,
18008 Granada, Spain
7
School of Physics and Astronomy, Queen Mary University of London,
327 Mile End Rd,
E1 4NS London, UK
8
Centro de Astrobiología (CSIC-INTA),
Camino Bajo del Castillo s/n, ESAC Campus,
28692 Villanueva,
Madrid, Spain
9
Instituto de Astrofísica de Canarias (IAC),
38205 La Laguna,
Tenerife, Spain
10
Departamento de Astrofísica, Universidad de La Laguna (ULL),
38206 La Laguna,
Tenerife, Spain
11
INAF – Osservatorio Astrofisico di Torino,
via Osservatorio 20,
10025 Pino Torinese, Italy
12
Institut für Astrophysik – Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
13
Thüringer Landessternwarte Tautenburg,
Sternwarte 5,
07778 Tautenburg,
Germany
14
Max-Planck-Institut für Astronomie,
Königstuhl 17,
69117 Heidelberg, Germany
15
Landessternwarte, Zentrum für Astronomie der Universtät Heidelberg,
Königstuhl 12,
69117 Heidelberg,
Germany
16
Departamento de Física de la Tierra y Astrofísica & UPARCOSUCM, Facultad de Ciencias Físicas, Universidad Complutense de Madrid,
28040 Madrid, Spain
17
Consejo Superior de Investigaciones Científicas (CSIC),
28006 Madrid,
Spain
18
Hamburger Sternwarte, Universität Hamburg,
Gojenbergsweg 112,
21029 Hamburg, Germany
19
Observatoire Astronomique de l’Université de Genève,
1290 Versoix,
Switzerland
20
Centro de Astrobiología (CSIC-INTA),
Carretera de Ajalvir km 4,
28850 Torrejón de Ardoz,
Madrid, Spain
Received:
2
February
2019
Accepted:
11
March
2019
Context. Small planets around low-mass stars often show orbital periods in a range that corresponds to the temperate zones of their host stars which are therefore of prime interest for planet searches. Surface phenomena such as spots and faculae create periodic signals in radial velocities and in observational activity tracers in the same range, so they can mimic or hide true planetary signals.
Aims. We aim to detect Doppler signals corresponding to planetary companions, determine their most probable orbital configurations, and understand the stellar activity and its impact on different datasets.
Methods. We analyzed 22 yr of data of the M1.5 V-type star Gl 49 (BD+61 195) including HARPS-N and CARMENES spectrographs, complemented by APT2 and SNO photometry. Activity indices are calculated from the observed spectra, and all datasets are analyzed with periodograms and noise models. We investigated how the variation of stellar activity imprints on our datasets. We further tested the origin of the signals and investigate phase shifts between the different sets. To search for the best-fit model we maximize the likelihood function in a Markov chain Monte Carlo approach.
Results. As a result of this study, we are able to detect the super-Earth Gl 49b with a minimum mass of 5.6 M⊕. It orbits its host star with a period of 13.85 d at a semi-major axis of 0.090 au and we calculate an equilibrium temperature of 350 K and a transit probability of 2.0%. The contribution from the spot-dominated host star to the different datasets is complex, and includes signals from the stellar rotation at 18.86 d, evolutionary timescales of activity phenomena at 40–80 d, and a long-term variation of at least four years.
Key words: planetary systems / techniques: radial velocities / stars: late-type / stars: activity / stars: individual: Gl 49 / methods: data analysis
Based on observations made with the Italian TNG, operated on the island of La Palma, Spain; the CARMENES instrument installed at the 3.5 m telescope of the Calar Alto Observatory, Spain; the robotic APT2 located at Serra La Nave on Mt. Etna, Italy; and the T90 telescope at Sierra Nevada Observatory, Spain.
Full Table A.1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/624/A123
© ESO 2019
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.