TOI-1080 b: a temperate, rocky planet orbiting a quiet M4V host

Journal article

We present the detection and validation of a small, temperate transiting exoplanet orbiting TOI-1080 every 3.9652482 d. The host is a quiet M4V star at 25.6 pc. The planet signal was first detected by the Transiting Exoplanet Survey Satellite (TESS) and validated using TESS and ground-based observations. By fitting the available light curves, the planet radius is measured to be 1.200 0.058 R and its equilibrium temperature of K. With Near Infra Red Planet Searcher (NIRPS) radial velocities, we are able to place a 3 upper limit on the mass of TOI-1080 b of 10.7 M. Our injection-recovery tests enable us to discard additional transiting planets in the TOI-1080 system with radii down to 0.9 R and periods between 0.5 and 7.7 d, and planets with radii larger than 1.4 R for periods up to 19 d. We demonstrate that it is highly amenable to characterization of its mass and putative atmosphere. In particular, we find that TOI-1080 b is an exceptional target for the ongoing JWST + HST Rocky Worlds DDT programme, having a priority score that is higher than four out of nine targets currently being investigated by the programme. TOI-1080 b can be added to the sample of nearby benchmark planets accessible for detailed study with JWST.

Authors: Gómez Maqueo Chew, Y; Dransfield, G; Barkaoui, K; Cadieux, C; Ducrot, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 548
• Issue: 1
• Pages: stag438
• Article number: stag438
• Publication date: 2026-03-06
• Acceptance date: 2026-02-26
• DOI: 10.1093/mnras/stag438
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: stars: individual: TOI-1080; techniques: photometric; stars: low-mass; exoplanets; techniques: spectroscopic; planetary systems