Discovering M-Dwarf Companions with STEPS

TL;DR

The STEPS survey uses high-precision astrometry to discover low-mass companions around M-dwarfs, successfully identifying and confirming objects like GJ 1210B through innovative measurement techniques.

Contribution

This paper introduces the STEPS astrometric method for detecting low-mass stellar companions around M-dwarfs, demonstrating its effectiveness with new discoveries.

Findings

Discovered low-mass companions around M-dwarfs using astrometry.

Confirmed GJ 1210B as a stellar companion through imaging.

Achieved ~1 milliarcsecond relative astrometry accuracy.

Abstract

The Stellar Planet Survey (STEPS) is an ongoing astrometric search for giant planets and brown dwarfs around a sample of ~30 M-dwarfs. We have discovered several low-mass companions by measuring the motion of our target stars relative to their reference frames. We describe the STEPS method for stellar centroiding that enables our ~1 milliarcsecond relative astrometry. We describe one of the astrometrically discovered companions, GJ 1210B, which was later confirmed with an imaging observation. GJ 1210 A and B have spectral types M4-5, based on their luminosities, inferred masses, and colors.