Title: HATS-3b: An inflated hot Jupiter transiting an F-type star Authors: D. Bayliss, G. Zhou, K. Penev, G. Bakos, J. Hartman, A. Jordán, L. Mancini, M. Mohler, V. Suc, M. Rabus, B. Béky, Z. Csubry, L. Buchhave, T. Henning, N. Nikolov, B. Csák, R. Brahm, N. Espinoza, R. Noyes, B. Schmidt, P. Conroy, D. Wright, C. Tinney, B. Addison, P. Sackett, D. Sasselov, J. Lázár, I. Papp, P. Sári

We report the discovery by the HATSouth survey of HATS-3b, a transiting extrasolar planet orbiting a V=12.4 F-dwarf star. HATS-3b has a period of P = 3.5479d, mass of Mp = 1.07 Jupiter masses, and radius of Rp = 1.38 Jupiter radii. Given the radius of the planet, the brightness of the host star, and the stellar rotational velocity (vsini = 9.0km/s), this system will make an interesting target for future observations to measure the Rossiter-McLaughlin effect and determine its spin-orbit alignment. We detail the low/medium-resolution reconnaissance spectroscopy that we are now using to deal with large numbers of transiting planet candidates produced by the HATSouth survey. We show that this important step in discovering planets produces logg and Teff parameters at a precision suitable for efficient candidate vetting, as well as efficiently identifying stellar mass eclipsing binaries with radial velocity semi-amplitudes as low as 1 km/s.

Title: A transit timing analysis of seven RISE light curves of the exoplanet system HAT-P-3 Authors: N. P. Gibson (1), D. Pollacco (1), S. Barros (1), C. Benn (2), D. Christian (3), M. Hrudková (4), Y. C. Joshi (1), F. P. Keenan (1), E. K. Simpson (1), I. Skillen (2), I. A. Steele (5), I. Todd (1) ((1) Queen's University Belfast, (2) Isaac Newton Group of Telescopes, (3) California State University Northridge, (4) Charles University Prague, (5) Liverpool John Moores University)

We present seven light curves of the exoplanet system HAT-P-3, taken as part of a transit timing program using the RISE instrument on the Liverpool Telescope. The light curves are analysed using a Markov-Chain Monte-Carlo algorithm to update the parameters of the system. The inclination is found to be i = 86.75^{+0.22}_{-0.21} deg, the planet-star radius ratio to be R_p/R_star = 0.1098^{+0.0010}_{-0.0012}, and the stellar radius to be R_star = 0.834^{+0.018}_{-0.026} R_sun, consistent with previous results but with a significant improvement in the precision. Central transit times and uncertainties for each light curve are also determined, and a residual permutation algorithm used as an independent check on the errors. The transit times are found to be consistent with a linear ephemeris, and a new ephemeris is calculated as T_c(0) = 2454856.70118 ±0.00018 HJD and P = 2.899738 ±0.000007 days. Model timing residuals are fitted to the measured timing residuals to place upper mass limits for a hypothetical perturbing planet as a function of the period ratio. These show that we have probed for planets with masses as low as 0.33 M_earth and 1.81 M_earth in the interior and exterior 2:1 resonances, respectively, assuming the planets are initially in circular orbits.