Updated parameters for the transiting exoplanet WASP-3b using RISE, a new fast camera for the Liverpool Telescope

TL;DR

This paper reports high-precision transit observations of exoplanet WASP-3b using the new RISE camera on the Liverpool Telescope, refining its physical parameters and transit timing with improved accuracy.

Contribution

It introduces the RISE camera for high time resolution photometry and provides updated planetary and orbital parameters for WASP-3b based on new transit data.

Findings

Planetary radius: 1.29 R_J

Transit inclination: 85.07 degrees

Refined orbital period and transit time

Abstract

Some of the first results are reported from RISE - a new fast camera mounted on the Liverpool Telescope primarily designed to obtain high time resolution light curves of transiting extrasolar planets for the purpose of transit timing. A full and partial transit of WASP-3 are presented, and a Monte Carlo Markov Chain analysis is used to update the parameters from the discovery paper. This results in a planetary radius of 1.29^{+0.05}_{-0.12} R_J and therefore a density of 0.82^{+0.14}_{-0.09} p_J, consistent with previous results. The inclination is 85.07^{+0.15}_{-0.16} deg, in agreement (but with a significant improvement in the precision) with the previously determined value. Central transit times are found to be consistent with the ephemeris given in the discovery paper. However, a new ephemeris calculated using the longer baseline results in T_c(0) = 2454605.55915 +- 0.00023 HJD and P = 1.846835 +- 0.000002 days.