Transiting exoplanets from the CoRoT space mission. XXVI. CoRoT-24: a transiting multiplanet system

We present the discovery of a candidate multiply transiting system, the first one found in the CoRoT mission. Two transit-like features with periods of 5.11 and 11.76 d are detected in the CoRoT light curve around a main sequence K1V star of r=15.1. If the features are due to transiting planets around the same star, these would correspond to objects of 3.7±0.4 and 5.0±0.5 R⊕ , respectively. Several radial velocities serve to provide an upper limit of 5.7 M⊕ for the 5.11 d signal and to tentatively measure a mass of 28+11 −11 M⊕ for the object transiting with a 11.76 d period. These measurements imply low density objects, with a significant gaseous envelope. The detailed analysis of the photometric and spectroscopic data serve to estimate the probability that the observations are caused by transiting Neptune-sized planets as >26× higher than a blend scenario involving only one transiting planet and >900× higher than a scenario involving two blends and no planets. The radial velocities show a long-term modulation that might be attributed to a 1.5 MJup planet orbiting at 1.8 A.U. from the host, but more data are required to determine the precise orbital parameters of this companion.

C. Moutou | D. Queloz | A. Santerne | T. Guillot | A. Erikson | S. Aigrain | L. Jorda | W. D. Cochran | M. Endl | M. Ollivier | H. Lammer | G. Wuchterl | H. Rauer | M. Deleuil | A. S. Bonomo | Sz. Csizmadia | A. Ofir | H. J. Deeg | M. Gillon | A. Baglin | M. Auvergne | S. Carpano | D. Rouan | J. M. Almenara | C. Lovis | M. Fridlund | C. Cavarroc | R. Titz-Weider | B. Tingley | R. Dvorak | P. Barge | F. Bouchy | D. Gandolfi | T. Pasternacki | J. Weingrill | E. W. Guenther | T. Guillot | A. Santerne | C. Moutou | F. Bouchy | G. H'ebrard | J. Almenara | A. Bonomo | M. Deleuil | R. D'iaz | D. Rouan | P. Bordé | M. Ollivier | T. Mazeh | S. Csizmadia | C. Lovis | W. Cochran | M. Endl | P. MacQueen | A. Ofir | M. Gillon | D. Queloz | J. Cabrera | R. Dvorak | D. Gandolfi | H. Rauer | A. Erikson | A. Hatzes | S. Aigrain | S. Grziwa | J. Cabrera | H. Deeg | M. Fridlund | E. Guenther | M. Patzold | H. Lammer | L. Jorda | J. Schneider | M. Auvergne | S. Ferraz-Mello | T. Fruth | P. Barge | G. H'ebrard | A. Baglin | S. Carpano | B. Tingley | G. Wuchterl | P. Bord'e | A. L'eger | R. Titz-Weider | C. Cavarroc | R. Alonso | A. Hatzes | T. Mazeh | J. Schneider | J. Cabrera | S. Ferraz-Mello | P. Bord'e | A. L'eger | M. Patzold | J. Weingrill | T. Pasternacki | R. F. D'iaz | M. Pätzold | P. J. MacQueen | P. Macqueen | S. Grziwa | T. Fruth | M. Tadeu dos Santos | M. Fridlund | S. Grziwa | J. Schneider | R. Alonso | A. Léger | G. Hébrard | A. Erikson | R. F. Díaz | M. T. Santos | Günther Wuchterl

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