A sub-Earth-mass planet orbiting Barnard's star: No evidence of transits in TESS photometry

TL;DR

This study analyzed TESS photometry of Barnard's star to detect transits of the recently announced sub-Earth-mass planet Barnard b, finding no evidence of transits and setting an upper limit on its orbital inclination.

Contribution

The paper provides the first TESS photometric analysis of Barnard's star, offering constraints on the transiting nature and orbital inclination of Barnard b.

Findings

No transits of Barnard b detected in TESS data.

Established an upper limit of 87.9 degrees for the orbital inclination.

Confirmed the flatness of the light curve with low noise levels.

Abstract

A sub-Earth-mass planet orbiting Barnard's star, designated as Barnard b, has been recently announced. At almost the same time, the first photometric data of Barnard's star by the Transit Exoplanet Survey Satellite (TESS) was released in Sector 80. We explore the possibility of emergent transits of Barnard b in TESS photometry. The detrended 2 min light curve appears to be flat, with a flux root mean square of 0.411 parts per thousand. Attempts of blind and informed transit-curve model inference suggest no evidence of transiting Barnard b, or any other body. This provides a 3$\sigma$ upper bound of 87.9 degrees for the orbital inclination of Barnard b.