Issue |
A&A
Volume 627, July 2019
|
|
---|---|---|
Article Number | A49 | |
Number of page(s) | 14 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/201935460 | |
Published online | 01 July 2019 |
The CARMENES search for exoplanets around M dwarfs
Two temperate Earth-mass planet candidates around Teegarden’s Star★
1
Institut für Astrophysik, Georg-August-Universität,
Friedrich-Hund-Platz 1,
37077
Göttingen, Germany
e-mail: zechmeister@astro.physik.uni-goettingen.de
2
Institut de Ciències de l’Espai (ICE, CSIC),
Campus UAB, C/Can Magrans s/n,
08193
Bellaterra,
Spain
3
Institut d’Estudis Espacials de Catalunya (IEEC),
08034
Barcelona,
Spain
4
Centro de Astrobiología (CSIC-INTA),
ESAC campus, Camino bajo del castillo s/n,
28692
Villanueva de la Cañada,
Madrid, Spain
5
Instituto de Astrofísica de Andalucía (IAA-CSIC),
Glorieta de la Astronomía s/n,
18008
Granada, Spain
6
Instituto de Astrofísica de Canarias (IAC),
Vía Láctea s/n,
38205
La Laguna,
Tenerife, Spain
7
Departamento de Astrofísica, Universidad de La Laguna (ULL),
38206
La Laguna,
Tenerife,
Spain
8
Department of Geophysics, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University,
Tel Aviv
6997801,
Israel
9
School of Physics and Astronomy, Queen Mary, University of London,
327 Mile End Road,
London,
E1 4NS,
UK
10
Landessternwarte, Zentrum für Astronomie der Universität Heidelberg,
Königstuhl 12,
69117
Heidelberg,
Germany
11
Centro Astronómico Hispano-Alemán (CSIC-MPG),
Observatorio Astronómico de Calar Alto,
Sierra de los Filabres-04550 Gérgal,
Almería, Spain
12
Leiden Observatory, Leiden University,
Postbus 9513,
2300 RA,
Leiden,
The Netherlands
13
Max-Planck-Institut für Sonnensystemforschung,
Justus-von-Liebig-Weg 3,
37077
Göttingen,
Germany
14
Departamento de Astronomía, Universidad de Chile,
Camino El Observatorio 1515,
Las Condes,
Santiago,
Chile
15
Instituto Nacional de Astrofísica, Óptica y Electrónica,
Luis Enrique Erro 1,
Sta. Ma. Tonantzintla,
Puebla,
Mexico
16
Departamento de Física de la Tierra y Astrofísica & IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos de la UCM), Facultad de Ciencias Físicas, Universidad Complutense de Madrid,
28040
Madrid,
Spain
17
Max-Planck-Institut für Astronomie,
Königstuhl 17,
69117
Heidelberg,
Germany
18
Thüringer Landessternwarte Tautenburg,
Sternwarte 5,
07778
Tautenburg,
Germany
19
Hamburger Sternwarte, Universität Hamburg,
Gojenbergsweg 112,
21029
Hamburg,
Germany
20
Department of Exploitation and Exploration of Mines, University of Oviedo,
Oviedo,
Spain
21
Department of Earth and Planetary Science, The University of Tokyo,
7-3-1 Hongo,
Bunkyo-ku,
Tokyo
113-0033,
Japan
22
Observatorio Astronómico Nacional (OAN-IGN),
Apartado 112,
28803
Alcalá de Henares,
Spain
23
FRACTAL SLNE. C/ Tulipán 2,
P13-1A,
28231
Las Rozas de Madrid,
Spain
24
Centro de Astrobiología (CSIC-INTA),
Carretera de Ajalvir km 4,
28850
Torrejón de Ardoz,
Madrid,
Spain
25
Institut für Theoretische Physik und Astrophysik,
Leibnizstraße 15,
24118
Kiel,
Germany
26
Institut für Astronomie und Astrophysik, Eberhard Karls Universität,
Sand 1,
72076
Tübingen,
Germany
27
Department of Signal Theory and Communications, Universidad Carlos III de Madrid, Av. de la Universidad 30,
28911
Leganés,
Spain
28
Gregorio Marañón Health Research Institute,
Doctor Esquerdo 46,
28007
Madrid,
Spain
29
Department of Physics, University of Rome Tor Vergata,
Via della Ricerca Scientifica 1,
00133
Rome, Italy
30
INAF – Osservatorio Astrofisico di Torino,
Via Osservatorio 20,
10025
Pino Torinese,
Italy
31
International Institute for Advanced Scientific Studies (IIASS),
Via G. Pellegrino 19,
84019
Vietri sul Mare (SA),
Italy
32
IES Montes Orientales, Departamento de Matemáticas,
Carretera de la Sierra 31,
18550
Iznalloz,
Granada,
Spain
33
Department of Astronomy, The University of Tokyo,
7-3-1 Hongo,
Bunkyo-ku,
Tokyo
113-0033,
Japan
34
Astrobiology Center,
2-21-1 Osawa,
Mitaka,
Tokyo
181-8588,
Japan
35
JST, PRESTO,
7-3-1 Hongo,
Bunkyo-ku,
Tokyo
113-0033,
Japan
36
National Astronomical Observatory of Japan,
2-21-1 Osawa,
Mitaka,
Tokyo
181-8588,
Japan
37
Weizmann Institute of Science,
234 Herzl Street,
Rehovot
761001,
Israel
38
School of Physics, University College Dublin,
Belfield,
Dublin 4,
Ireland
39
European Southern Observatory,
Alonso de Córdova 3107,
Vitacura,
Casilla
19001, Santiago de Chile, Chile
40
Diseño Sistemas Ópticos,
Maria Moliner 9B,
41008
Sevilla,
Spain
41
The Department of Astronomy and Astrophysics, University of Chicago,
5640 S. Ellis Ave,
Chicago,
IL
60637,
USA
42
Universidad de Granada,
Av. del Hospicio, s/n,
18010
Granada,
Spain
43
Optical System Engineering,
Kirchenstr. 6,
74937
Spechbach,
Germany
Received:
13
March
2019
Accepted:
14
May
2019
Context. Teegarden’s Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V), the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.
Aims. As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden’s Star and analysed them for planetary signals.
Methods. We find periodic variability in the radial velocities of Teegarden’s Star. We also studied photometric measurements to rule out stellar brightness variations mimicking planetary signals.
Results. We find evidence for two planet candidates, each with 1.1 M⊕ minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. No evidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotation and old age.
Conclusions. The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cool dwarf for which the masses have been determined using radial velocities.
Key words: methods: data analysis / planetary systems / stars: late-type / stars: individual: Teegarden’s Star
Tables D.1 and D.2 are 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/627/A49
© 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.