An ablating super-Earth in an eccentric binary from the Dispersed Matter Planet Project

TL;DR

This paper reports the discovery of a hot super-Earth orbiting a star in a binary system, with evidence of planetary ablation and complex dynamical interactions, advancing understanding of low-mass exoplanets in binary environments.

Contribution

It presents the first detection of a super-Earth in an eccentric binary system with detailed characterization and insights into planetary ablation processes.

Findings

Discovery of a super-Earth in a binary system with a 6.67-day orbit.

Evidence of planetary ablation from circumstellar absorption.

The system's configuration suggests complex dynamical history.

Abstract

Earth mass exoplanets are difficult to detect. The Dispersed Matter Planet Project (DMPP) identifies stars which are likely to host the most detectable low mass exoplanets. The star DMPP-3 (HD 42936) shows signs of circumstellar absorption, indicative of mass loss from ablating planets. Here we report the radial velocity (RV) discovery of a highly eccentric 507 d binary companion and a hot super-Earth planet in a 6.67 d orbit around the primary star. DMPP-3A is a solar type star while DMPP-3B is just massive enough to fuse hydrogen. The binary, with semi-major axis 1.22 $\pm$ 0.02 AU, is considerably tighter than others known to host planets orbiting only one of the component stars. The configuration of the DMPP-3 planetary system is rare and indicates dynamical interactions, though the evolutionary history is not entirely clear. DMPP-3Ab is possibly the residual core of a giant planet precursor, consistent with the inferred circumstellar gas shroud.