NGTS and WASP photometric recovery of a single-transit candidate from TESS

Hellier

Abstract

The Transiting Exoplanet Survey Satellite (TESS) produces a large number of single-transit event candidates, since the mission monitors most stars for only ~27 d. Such candidates correspond to long-period planets or eclipsing binaries. Using the TESS Sector 1 full-frame images, we identified a 7750 ppm single-transit event with a duration of 7 h around the moderately evolved F-dwarf star TIC-238855958 (Tmag = 10.23, Teff = 6280 ± 85 K). Using archival WASP photometry we constrained the true orbital period to one of three possible values. We detected a subsequent transit-event with NGTS, which revealed the orbital period to be 38.20 d. Radial velocity measurements from the CORALIE Spectrograph show the secondary object has a mass of M2 = 0.148 ± 0.003 M?, indicating this system is an F–M eclipsing binary. The radius of the M-dwarf companion is R2 = 0.171 ± 0.003 R?, making this one of the most well characterized stars in this mass regime. We find that its radius is 2.3s lower than expected from stellar evolution models.

Citation

Hellier. (2019). NGTS and WASP photometric recovery of a single-transit candidate from TESS. Monthly Notices of the Royal Astronomical Society, 1548 - 1553. https://doi.org/10.1093/mnras/stz3212

• Acceptance Date: Nov 13, 2019
• Publication Date: Nov 19, 2019
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Pages: 1548 - 1553
• DOI: https://doi.org/10.1093/mnras/stz3212
• Keywords: NGTS, WASP, photometric, single-transit, TESS.
• Publisher URL: https://doi.org/10.1093/mnras/stz3212