WASP-43b: The closest-orbiting hot Jupiter

TL;DR

This paper reports the discovery of WASP-43b, a hot Jupiter with the shortest orbital distance known, orbiting a low-mass K7V star, highlighting the existence of such planets around stars with deep convection zones.

Contribution

The discovery of WASP-43b, the closest-orbiting hot Jupiter around a low-mass star, expands understanding of planetary systems around stars with deep convection zones.

Findings

WASP-43b has the shortest known orbital distance for a hot Jupiter.

The host star is the lowest-mass star known to host a hot Jupiter.

The planet's orbit suggests potential for tidal decay studies.

Abstract

We report the discovery of WASP-43b, a hot Jupiter transiting a K7V star every 0.81 d. At 0.6-Msun the host star has the lowest mass of any star hosting a hot Jupiter. It also shows a 15.6-d rotation period. The planet has a mass of 1.8 Mjup, a radius of 0.9 Rjup, and with a semi-major axis of only 0.014 AU has the smallest orbital distance of any known hot Jupiter. The discovery of such a planet around a K7V star shows that planets with apparently short remaining lifetimes owing to tidal decay of the orbit are also found around stars with deep convection zones.