Transiting exoplanets from the CoRoT space mission XXV. C0R0T-27b: a massive and dense planet on a short-period orbit
H. Parviainen
,
D. Gandolfi
(1)
,
M. Deleuil
(2)
,
C. Moutou
(2)
,
H. J. Deeg
(3)
,
S. Ferraz-Mello
(4)
,
B. Samuel
(5)
,
Sz. Csizmadia
,
T. Pasternacki
,
G. Wuchterl
(6)
,
M. Havel
(7)
,
M. Fridlund
(8)
,
R. Angus
,
B. Tingley
,
S. Grziwa
,
J. Korth
,
S. Aigrain
,
J. M. Almenara
(2)
,
R. Alonso
(9)
,
A. Baglin
(5)
,
S. C. C. Barros
(2)
,
P. Borde
,
F. Bouchy
(10, 3)
,
Justo Cabrera
(11)
,
R. F. Diaz
,
R. Dvorak
(12)
,
A. Erikson
(13)
,
T. Guillot
(14)
,
A. Hatzes
(6)
,
G. Hébrard
(3)
,
T. Mazeh
,
G. Montagnier
(15)
,
A. Ofir
,
M. Ollivier
(16)
,
M. Paetzold
(17)
,
H. Rauer
(18)
,
D. Rouan
(5)
,
A. Santerne
(19)
,
J. Schneider
(20)
1
Department of Brain and Behavioural Sciences
2 LAM - Laboratoire d'Astrophysique de Marseille
3 IAP - Institut d'Astrophysique de Paris
4 IAG - Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo]
5 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
6 TLS - Thüringer Landessternwarte Tautenburg
7 CASSIOPEE - Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides
8 RSSD - Research and Scientific Support Department, ESTEC
9 CBMSO - Centro de Biología Molecular Severo Ochoa [Madrid]
10 OHP - Observatoire de Haute-Provence
11 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
12 Institute of Astronomy
13 DLR Institute of Planetary Research
14 LAGRANGE - Joseph Louis LAGRANGE
15 ESO - European Southern Observatory
16 LTM - Laboratoire des technologies de la microélectronique
17 Universität zu Köln = University of Cologne
18 DLR Institut für Planetenforschung
19 CAUP - Centro de Astrofísica da Universidade do Porto
20 LUTH (UMR_8102) - Laboratoire Univers et Théories
2 LAM - Laboratoire d'Astrophysique de Marseille
3 IAP - Institut d'Astrophysique de Paris
4 IAG - Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo]
5 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
6 TLS - Thüringer Landessternwarte Tautenburg
7 CASSIOPEE - Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides
8 RSSD - Research and Scientific Support Department, ESTEC
9 CBMSO - Centro de Biología Molecular Severo Ochoa [Madrid]
10 OHP - Observatoire de Haute-Provence
11 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
12 Institute of Astronomy
13 DLR Institute of Planetary Research
14 LAGRANGE - Joseph Louis LAGRANGE
15 ESO - European Southern Observatory
16 LTM - Laboratoire des technologies de la microélectronique
17 Universität zu Köln = University of Cologne
18 DLR Institut für Planetenforschung
19 CAUP - Centro de Astrofísica da Universidade do Porto
20 LUTH (UMR_8102) - Laboratoire Univers et Théories
H. Parviainen
- Fonction : Auteur
D. Gandolfi
- Fonction : Auteur
- PersonId : 761173
- ORCID : 0000-0001-8627-9628
M. Deleuil
- Fonction : Auteur
- PersonId : 174546
- IdHAL : magali-deleuil
- ORCID : 0000-0001-6036-0225
- IdRef : 095234209
C. Moutou
- Fonction : Auteur
- PersonId : 1156835
- IdHAL : claire-moutou
- ORCID : 0000-0002-2842-3924
- IdRef : 10151218X
Sz. Csizmadia
- Fonction : Auteur
T. Pasternacki
- Fonction : Auteur
M. Fridlund
- Fonction : Auteur
- PersonId : 760393
- ORCID : 0000-0002-0855-8426
- IdRef : 095236449
R. Angus
- Fonction : Auteur
B. Tingley
- Fonction : Auteur
S. Grziwa
- Fonction : Auteur
J. Korth
- Fonction : Auteur
- PersonId : 774407
- ORCID : 0000-0002-0076-6239
S. Aigrain
- Fonction : Auteur
J. M. Almenara
- Fonction : Auteur
- PersonId : 760392
- ORCID : 0000-0003-3208-9815
P. Borde
- Fonction : Auteur
R. F. Diaz
- Fonction : Auteur
T. Guillot
- Fonction : Auteur
- PersonId : 16166
- IdHAL : tristanguillot
- ORCID : 0000-0002-7188-8428
- IdRef : 110334965
T. Mazeh
- Fonction : Auteur
A. Ofir
- Fonction : Auteur
Résumé
Aims. We report the discovery of a massive and dense transiting planet CoRoT-27b on a 3.58-day orbit around a 4.2 Gyr-old G2 star. The planet candidate was identified from the CoRoT photometry, and was confirmed as a planet with ground-based spectroscopy. Methods. The confirmation of the planet candidate is based on radial velocity observations combined with imaging to rule out blends. The characterisation of the planet and its host star was carried out using a Bayesian approach where all the data (CoRoT photometry, radial velocities, and spectroscopic characterisation of the star) are used jointly. The Bayesian analysis included a study whether the assumption of white normally distributed noise holds for the CoRoT photometry and whether the use of a non-normal noise distribution offers advantages in parameter estimation and model selection. Results. CoRoT-27b has a mass of 10.39 +/- 0.55 M-Jup, a radius of 1.01 +/- 0.04 R-Jup, a mean density of 12.6(-1.67)(+1.92) g cm(-3), and an effective temperature of 1500 +/- 130 K. The planet orbits around its host star, a 4.2 Gyr-old G2-star with a mass M-star = 1.06 M-circle dot and a radius R-star = 1.05 R-circle dot, on a 0.048 +/- 0.007 AU orbit of 3.58 days. The radial velocity observations allow us to exclude highly eccentric orbits, namely, e \textless0.065 with 99% confidence. Given its high mass and density, theoretical modelling of CoRoT-27b is demanding. We identify two solutions with heavy element mass fractions of 0.11 +/- 0.08 M-circle plus, and 0.07 +/- 0.06 M-circle plus, but even solutions void of heavy elements cannot be excluded. We carry out a secondary eclipse search from the CoRoT photometry using a method based on Bayesian model selection, but conclude that the noise level is too high to detect eclipses shallower than 9% of the transit depth. Using a non-normal noise model was shown not to affect the parameter estimation results, but led to significant improvement in the sensitivity of the model selection process.