A Third Exoplanetary System with Misaligned Orbital and Stellar Spin Axes

TL;DR

This paper provides evidence that the WASP-14 exoplanetary system has a significant misalignment between its orbital plane and stellar rotation axis, indicating different migration histories for massive eccentric planets.

Contribution

It reports the third known system with a misaligned orbit, highlighting the distinct evolution of massive, eccentric exoplanets compared to typical close-in Jupiters.

Findings

WASP-14 has a spin-orbit angle of 33.1 +/- 7.4 degrees.

WASP-14 is the third system with a significant misalignment.

All three misaligned systems host super-Jupiter planets with eccentric orbits.

Abstract

We present evidence that the WASP-14 exoplanetary system has misaligned orbital and stellar-rotational axes, with an angle lambda = 33.1 +/- 7.4 deg between their sky projections. The evidence is based on spectroscopic observations of the Rossiter-McLaughlin effect as well as new photometric observations. WASP-14 is now the third system known to have a significant spin-orbit misalignment, and all three systems have "super-Jupiter" planets (M_P > 3 Mjup) and eccentric orbits. This finding suggests that the migration and subsequent orbital evolution of massive, eccentric exoplanets is somehow different from that of less massive close-in Jupiters, the majority of which have well-aligned orbits.