Letter to the Editor

A sub-Earth-mass planet orbiting Barnard’s star

No evidence of transits in TESS photometry

¹ Instituto de Astrofísica de Canarias, 38205 La Laguna, Spain
² Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Spain
³ Light Bridges S. L., 35004 Las Palmas de Gran Canaria, Spain
⁴ Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
⁵ INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese, Italy
⁶ Centro de Astrobiología (CAB), CSIC-INTA, ESAC campus, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Spain
⁷ Instituto de Astrofísica e Ciências do Espaço, CAUP, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
⁸ Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
⁹ Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
¹⁰ Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal

^⋆ Corresponding author; atanas.stefanov@iac.es

Received: 1 October 2024
Accepted: 28 November 2024

Abstract

A sub-Earth-mass planet orbiting Barnard’s star, designated as Barnard b, has recently been 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 3σ upper bound of 87.9 degrees for the orbital inclination of Barnard b.