Issue |
A&A
Volume 579, July 2015
|
|
---|---|---|
Article Number | A36 | |
Number of page(s) | 19 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/201424501 | |
Published online | 23 June 2015 |
Transiting exoplanets from the CoRoT space mission ⋆,⋆⋆
XXVII. CoRoT-28b, a planet orbiting an evolved star, and CoRoT-29b, a planet showing an asymmetric transit
1
Institute of Planetary Research, German Aerospace
Center, Rutherfordstrasse
2, 12489
Berlin,
Germany
e-mail: juan.cabrera@dlr.de
2
Institut d’Astrophysique de Paris, UMR 7095 CNRS, Université
Pierre & Marie Curie, 98bis
boulevard Arago, 75014
Paris,
France
3
Leiden Observatory, University of Leiden,
PO Box 9513, 2300 RA, Leiden, The Netherlands
4
Department of Earth and Space Sciences, Chalmers University of
Technology, Onsala Space Observatory, 439 92
Onsala,
Sweden
5
Max Planck Institute for Astronomy Königstuhl 17,
69117
Heidelberg,
Germany
6
Thüringer Landessternwarte, Sternwarte 5, 07778
Tautenburg,
Germany
7
LESIA, UMR 8109 CNRS, Observatoire de Paris, UPMC, Université
Paris-Diderot, 5 place J.
Janssen, 92195
Meudon,
France
8
Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique
de Marseille) UMR 7326, 13388
Marseille,
France
9
IAG-Universidade de Sao Paulo, 05508-090
Sao Paulo,
Brasil
10
Zentrum für Astronomie, Fakultät für Physik und
Astronomie, Mönchhofstr.
12-14, 69120
Heidelberg,
Germany
11
Université de Nice-Sophia Antipolis, CNRS UMR 6202, Observatoire
de la Côte d’Azur, BP
4229, 06304
Nice Cedex 4,
France
12
Österreichische Akademie der Wissenschaften, Institut für
Weltraumforschung, IWF,
Schmiedlstraße 6, 8042
Graz,
Austria
13
Instituto de Astrofísica de Canarias, 38205, La
Laguna, Tenerife, Spain
14
Dept. Astrofísica, Universidad de la Laguna,
38206, La Laguna, Tenerife,
Spain
15
Sub-department of Astrophysics, Department of Physics, University
of Oxford, Oxford,
OX1 3RH,
UK
16
Rheinisches Institut fürUmweltforschung an der Universität zu
Köln, 50931
Aachener Strasse 209,
Germany
17
University of Hawaii, Institute for Astronomy,
34 Ohia Ku Street, Pukalani, Hawaii
96768,
USA
18
Las Cumbres Observatory Global Telescope Network,
Inc. 6740 Cortona Drive Suite
102, Goleta,
CA
93117,
USA
19
INAF–Osservatorio Astrofisico di Torino,
via Osservatorio 20,
10025
Pino Torinese,
Italy
20
LAB, UMR 5804, Univ. Bordeaux & CNRS,
33270
Floirac,
France
21
Institut d’Astrophysique Spatiale, Université Paris-Sud &
CNRS, 91405
Orsay,
France
22
Max-Planck-Institut für extraterrestrische Physik,
Giessenbachstrasse 1,
85748
Garching,
Germany
23
Torrance High School, 2200 W Carson St, Torrance, CA
90501,
USA
24
Observatoire de l’Université de Genève,
51 chemin des Maillettes,
1290
Sauverny,
Switzerland
25
University of Vienna, Institute of Astronomy,
Türkenschanzstr. 17,
1180
Vienna,
Austria
26
Iolani School, 563 Kamoku St., Honolulu, HI-96816, USA
27
School of Physics and Astronomy, Raymond and Beverly Sackler
Faculty of Exact Sciences, Tel Aviv University, 6997801
Tel Aviv,
Israel
28
CFHT Corporation, 65-1238 Mamalahoa Hwy,
Kamuela, Hawaii
96743,
USA
29
Institut für Astrophysik, Friedrich-Hund-Platz 1, 37077
Göttingen,
Germany
30
Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr.
36, 10623
Berlin,
Germany
31
Instituto de Astrofísica e Ciências do Espaço, Universidade do
Porto, CAUP, Rua das
Estrelas, 4150-762
Porto,
Portugal
32
LUTH, Observatoire de Paris, UMR 8102 CNRS, Université Paris
Diderot, 5 place Jules
Janssen, 92195
Meudon,
France
Received: 30 June 2014
Accepted: 30 March 2015
Context. We present the discovery of two transiting extrasolar planets by the satellite CoRoT.
Aims. We aim at a characterization of the planetary bulk parameters, which allow us to further investigate the formation and evolution of the planetary systems and the main properties of the host stars.
Methods. We used the transit light curve to characterize the planetary parameters relative to the stellar parameters. The analysis of HARPS spectra established the planetary nature of the detections, providing their masses. Further photometric and spectroscopic ground-based observations provided stellar parameters (log g, Teff, v sin i) to characterize the host stars. Our model takes the geometry of the transit to constrain the stellar density into account, which when linked to stellar evolutionary models, determines the bulk parameters of the star. Because of the asymmetric shape of the light curve of one of the planets, we had to include the possibility in our model that the stellar surface was not strictly spherical.
Results. We present the planetary parameters of CoRoT-28b, a Jupiter-sized planet (mass 0.484 ± 0.087 MJup; radius 0.955 ± 0.066 RJup) orbiting an evolved star with an orbital period of 5.208 51 ± 0.000 38 days, and CoRoT-29b, another Jupiter-sized planet (mass 0.85 ± 0.20 MJup; radius 0.90 ± 0.16 RJup) orbiting an oblate star with an orbital period of 2.850 570 ± 0.000 006 days. The reason behind the asymmetry of the transit shape is not understood at this point.
Conclusions. These two new planetary systems have very interesting properties and deserve further study, particularly in the case of the star CoRoT-29.
Key words: planetary systems / techniques: photometric / techniques: radial velocities / techniques: spectroscopic
The CoRoT space mission, launched on December 27th 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany, and Spain. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in time allocated by OPTICON and the Spanish Time Allocation Committee (CAT). The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement number RG226604 (OPTICON). This work makes use of observations from the LCOGT network.
Appendices are available in electronic form at http://www.aanda.org
© ESO, 2015
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