INVESTIGADORES
DIAZ Rodrigo Fernando
artículos
Título:
SOPHIE velocimetry of Kepler transit candidates. VI. An additional companion in the KOI-13 system
Autor/es:
A. SANTERNE; C. MOUTOU; S. C. C. BARROS; C. DAMIANI; R. F. DÍAZ; J. M. ALMENARA; A. S. BONOMO; F. BOUCHY; M. DELEUIL; G. HÉBRARD
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Lugar: Paris; Año: 2012 vol. 544 p. 1 - 4
ISSN:
0004-6361
Resumen:
We report the discovery of a new stellar companion in the KOI-13 system.
KOI-13 is composed of two fast-rotating A-type stars of similar
magnitude. One of these two stars hosts a transiting planet discovered
by Kepler. We obtained new radial velocity measurements using the SOPHIE
spectrograph at the Observatoire de Haute-Provence that reveal an
additional companion in this system. This companion has a mass of
between 0.4 Msun and 1 Msun and orbits one of
the two main stars with a period of 65.831 ± 0.029 days and an
eccentricity of 0.52 ± 0.02. The radial velocities of the two
stars are derived using a model of two fast-rotating line profiles. From
the residuals, we find a hint of the stellar variations seen in the
Kepler light curve, which have an amplitude of about 1.41 km
s-1 and a period close to the rotational period. This signal
appears to be about three orders of magnitude larger than expected for
stellar activity. From the analysis of the residuals, we also put a
3-σ upper limit on the mass of the transiting planet KOI-13.01 of
14.8 MJup and 9.4 MJup, depending on which star
hosts the transit. We find that this new companion has no significant
impact on the photometric determination of the mass of KOI-13.01 but is
expected to affect precise infrared photometry. Finally, using dynamical
simulations, we infer that the new companion is orbiting around KOI-13B
and that the transiting planet candidate is expected to orbit KOI-13A.
Thus, the transiting planet candidate KOI-13.01 is orbiting the main
component of a hierarchical triple system.