HATS-3b: An inflated hot Jupiter transiting an F-type star

TL;DR

The paper reports the discovery of HATS-3b, an inflated hot Jupiter orbiting an F-type star, highlighting its potential for future spin-orbit alignment studies and detailing the spectroscopic vetting process used in the survey.

Contribution

This work presents the discovery of a new hot Jupiter, HATS-3b, and introduces an efficient spectroscopic method for vetting transiting planet candidates.

Findings

HATS-3b is a hot Jupiter with a 3.55-day period, 1.07 Jupiter masses, and 1.38 Jupiter radii.

The host star is an F-dwarf with V=12.4, suitable for Rossiter-McLaughlin effect measurements.

The spectroscopic vetting method effectively identifies stellar binaries and characterizes candidates.

Abstract

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 = 1.07MJ, and radius of Rp = 1.38RJ. 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.