High-precision photometry by telescope defocussing. III. The transiting planetary system WASP-2
Abstract
We present high-precision photometry of three transits of the extrasolar planetary system WASP-2, obtained by defocussing the telescope, and achieving point-to-point scatters of between 0.42 and 0.73 mmag. These data are modelled using the JKTEBOP code, and taking into account the light from the recently-discovered faint star close to the system. The physical properties of the WASP-2 system are derived using tabulated predictions from five different sets of stellar evolutionary models, allowing both statistical and systematic errorbars to be specified. We find the mass and radius of the planet to be M_b = 0.847 +/- 0.038 +/- 0.024 Mjup and R_b = 1.044 +/- 0.029 +/- 0.015 Rjup. It has a low equilibrium temperature of 1280 +/- 21 K, in agreement with a recent finding that it does not have an atmospheric temperature inversion. The first of our transit datasets has a scatter of only 0.42 mmag with respect to the best-fitting light curve model, which to our knowledge is a record for ground-based observations of a transiting extrasolar planet.
Keywords
Cite
@article{arxiv.1006.4464,
title = {High-precision photometry by telescope defocussing. III. The transiting planetary system WASP-2},
author = {John Southworth and L. Mancini and S. Calchi Novati and M. Dominik and M. Glitrup and T. C. Hinse and U. G. Jorgensen and M. Mathiasen and D. Ricci and G. Maier and F. Zimmer and V. Bozza and P. Browne and I. Bruni and M. Burgdorf and M Dall'Ora and F. Finet and K. Harpsoe and M. Hundertmark and C. Liebig and S. Rahvar and G. Scarpetta and J. Skottfelt and B. Smalley and C. Snodgrass and J. Surdej},
journal= {arXiv preprint arXiv:1006.4464},
year = {2015}
}
Comments
Accepted for publication in MNRAS. 9 pages, 3 figures, 10 tables