WASP-19b: the shortest period transiting exoplanet yet discovered

TL;DR

This paper reports the discovery of WASP-19b, the shortest period transiting exoplanet known, with detailed characterization of its properties and host star, providing insights into tidal interactions and stellar evolution.

Contribution

It presents the discovery and detailed analysis of WASP-19b, the shortest period transiting exoplanet, including its physical parameters and host star characteristics.

Findings

WASP-19b has an orbital period of approximately 0.79 days.

The host star is a G-dwarf with super-solar metallicity.

The system's properties suggest possible tidal interactions affecting stellar rotation.

Abstract

We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass Mpl = 1.15 \pm 0.08 MJ, radius Rpl = 1.31 \pm 0.06 RJ, and orbital period P = 0.7888399 \pm 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 \pm 0.1 dex) G-dwarf with Teff = 5500 \pm 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of Prot = 10.5 \pm 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (~ 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q's, if a more precise age is determined.