Refined physical properties of the HATP13 planetary system
Abstract
We present photometry of four transits of the planetary system HATP13, obtained using defocused telescopes. We analyse these, plus nine data sets from the literature, in order to determine the physical properties of the system. The mass and radius of the star are M_{A}= 1.320 ± 0.048 ± 0.039 M_{⊙} and R_{A}= 1.756 ± 0.043 ± 0.017 R_{⊙} (statistical and systematic error bars). We find the equivalent quantities for the transiting planet to be M_{b}= 0.906 ± 0.024 ± 0.018 M_{Jup} and R_{b}= 1.487 ± 0.038 ± 0.015 R_{Jup}, with an equilibrium temperature of ? K. Compared to previous results, which were based on much sparser photometric data, we find the star to be more massive and evolved, and the planet to be larger, hotter and more rarefied. The properties of the planet are not matched by standard models of irradiated gas giants. Its large radius anomaly is in line with the observation that the hottest planets are the most inflated, but at odds with the suggestion of inverse proportionality to the [Fe/H] of the parent star. We assemble all available times of transit midpoint and determine a new linear ephemeris. Previous findings of transit timing variations in the HATP13 system are shown to disagree with these measurements, and can be attributed to smallnumber statistics.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 March 2012
 DOI:
 10.1111/j.13652966.2011.20230.x
 arXiv:
 arXiv:1111.5432
 Bibcode:
 2012MNRAS.420.2580S
 Keywords:

 stars: fundamental parameters;
 stars: individual: HATP13;
 planetary systems;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 Accepted for publication in MNRAS. 8 pages, 5 tables, 3 figures. The results have been included in the TEPCat catalogue of transiting planets at http://www.astro.keele.ac.uk/~jkt/tepcat/