Bibcode
Maciejewski, G.; Raetz, St.; Nettelmann, N.; Seeliger, M.; Adam, C.; Nowak, G.; Neuhäuser, R.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 535, id.A7, 10 pp.
Fecha de publicación:
11
2011
Revista
Número de citas
21
Número de citas referidas
17
Descripción
Context. The WASP-10 planetary system is intriguing because different
values of radius have been reported for its transiting exoplanet. The
host star exhibits activity in terms of photometric variability, which
is caused by the rotational modulation of the spots. Moreover, a
periodic modulation has been discovered in transit timing of WASP-10 b,
which could be a sign of an additional body perturbing the orbital
motion of the transiting planet. Aims: We attempt to refine the
physical parameters of the system, in particular the planetary radius,
which is crucial for studying the internal structure of the transiting
planet. We also determine new mid-transit times to confirm or refute
observed anomalies in transit timing. Methods: We acquired
high-precision light curves for four transits of WASP-10 b in 2010.
Assuming various limb-darkening laws, we generated best-fit models and
redetermined parameters of the system. The prayer-bead method and Monte
Carlo simulations were used to derive error estimates. Results:
Three transit light curves exhibit signatures of the occultations of
dark spots by the planet during its passage across the stellar disk. The
influence of stellar activity on transit depth is taken into account
while determining system parameters. The radius of WASP-10 b is found to
be no greater than 1.03+0.07-0.03 Jupiter radii, a
value significantly smaller than most previous studies indicate. We
calculate interior structure models of the planet, assuming a two-layer
structure with one homogeneous envelope atop a rock core. The high value
of the WASP-10 b's mean density allows one to consider the planet's
internal structure including 270 to 450 Earth masses of heavy elements.
Our new mid-transit times confirm that transit timing cannot be
explained by a constant period if all literature data points are
considered. They are consistent with the ephemeris assuming a periodic
variation of transit timing. We show that possible starspot features
affecting the transit's ingress or egress cannot reproduce variations in
transit timing at the observed amplitude.
Based on observations collected at the Centro Astronómico Hispano
Alemán (CAHA), operated jointly by the Max-Planck Institut
für Astronomie and the Instituto de Astrofisica de Andalucia
(CSIC).Photometric data are available in electronic form 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/535/A7