Refining Parameters of the XO-5 Planetary System with High-Precision Transit Photometry

TL;DR

This study refines the parameters of the XO-5 b exoplanet using high-precision transit photometry, confirming its high Safronov number and surface gravity, and finds no evidence of transit timing variations.

Contribution

The paper provides more accurate measurements of XO-5 b's physical parameters and refines its orbital ephemeris using new high-precision transit data.

Findings

XO-5 b has a radius of approximately 1.03 Jupiter radii.

The planet's high Safronov number and surface gravity are confirmed.

No significant transit timing variations were detected.

Abstract

Studies of transiting extrasolar planets offer an unique opportunity to get to know the internal structure of those worlds. The transiting exoplanet XO-5 b was found to have an anomalously high Safronov number and surface gravity. Our aim was to refine parameters of this intriguing system and search for signs of transit timing variations. We gathered high-precision light curves of two transits of XO-5 b. Assuming three different limb darkening laws, we found the best-fitting model and redetermined parameters of the system, including planet-to-star radius ratio, impact parameter and central time of transits. Error estimates were derived by the prayer bead method and Monte Carlo simulations. Although system's parameters obtained by us were found to agree with previous studies within one sigma, the planet was found to be notable smaller with the radius of 1.03+0.06-0.05 Jupiter radii. Our results confirm the high Safronov number and surface gravity of the planet. With two new mid-transit times, the ephemeris was refined to BJD(TDB)=(2454485.66842 \pm 0.00028) + (4.1877537 \pm 0.000017) E. No significant transit timing variation was detected.