Dispersed Matter Planet Project Discoveries of Ablating Planets Orbiting Nearby Bright Stars

TL;DR

The Dispersed Matter Planet Project identifies and characterizes ablating, mass-losing exoplanets around nearby bright stars using high-precision radial velocity measurements, revealing a new method for detecting compact planetary systems and studying their composition.

Contribution

This study introduces a novel detection method for ablating exoplanets via circumstellar gas absorption, validated by statistics and detailed observations of specific planetary systems.

Findings

Detected a planet with 0.469 M_J in a 5.207-day orbit around HD 11231.

Found short-period planets consistently where extensive RV measurements were made.

Validated the hypothesis that circumstellar gas absorption indicates mass-losing planets.

Abstract

Some highly irradiated close-in exoplanets orbit stars showing anomalously low stellar chromospheric emission. We attribute this to absorption by circumstellar gas replenished by mass loss from ablating planets. Here we report statistics validating this hypothesis. Among ~3000 nearby, bright, main sequence stars ~40 show depressed chromospheric emission indicative of undiscovered mass-losing planets. The Dispersed Matter Planet Project uses high precision, high cadence radial velocity measurements to detect these planets. We summarise results for two planetary systems (DMPP-1 and DMPP-3) and fully present observations revealing a Mp sin i = 0.469 M$_{\rm J}$ planet in a 5.207 d orbit around the $\gamma$-Doradus pulsator HD 11231 (DMPP-2). We have detected short period planets wherever we have made more than 60 RV measurements, demonstrating that we have originated a very efficient method for detecting nearby compact planetary systems. Our shrouded, ablating planetary systems may be a short-lived phase related to the Neptunian desert: i.e. the dearth of intermediate-mass planets at short orbital periods. The circumstellar gas facilitates compositional analysis; allowing empirical exogeology in the cases of sublimating rocky planets. Dispersed Matter Planet Project discoveries will be important for establishing the empirical mass-radius-composition relationship(s) for low mass planets.