Astrophysics, abstract
astro-ph/0607571

From: Matthew J. Holman [view email]

Date: Tue, 25 Jul 2006 20:01:44 GMT (127kb)

The Transit Light Curve (TLC) Project. I. Four Consecutive Transits of the Exoplanet XO-1b

Authors: Matthew J. Holman, Joshua N. Winn, David W. Latham, Francis T. O'Donovan, David Charbonneau, Gaspar A. Bakos, Gilbert A. Esquerdo, Carl Hergenrother, Mark E. Everett, Andras Pal

Comments: 22 pages, 5 figures, 2 tables. Accepted for publication in ApJ

We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve upon the estimates of the transit parameters, finding the planetary radius to be R_P = 1.184 +0.028/-0.018 R_Jupiter and the stellar radius to be R_S = 0.928 +0.018/-0.013 R_Sun, assuming a stellar mass of M_S = 1.00 +/- 0.03 M_Sun. The uncertainties in the planetary and stellar radii are dominated by the uncertainty in the stellar mass. These uncertainties increase by a factor of 2-3 if a more conservative uncertainty of 0.10 M_Sun is assumed for the stellar mass. Our estimate of the planetary radius is smaller than that reported by McCullough et al. (2006) and yields a mean density that is comparable to that of TrES-1 and HD 189733b. The timings of the transits have an accuracy ranging from 0.2 to 2.5 minutes, and are marginally consistent with a uniform period.

http://arxiv.org/abs/astro-ph/0607571