NGTS and WASP photometric recovery of a single-transit candidate from TESS. Issue 2 (19th November 2019)

• Record Type: Journal Article
• Authors: Gill, Samuel; Bayliss, Daniel; Cooke, Benjamin F; Wheatley, Peter J; Nielsen, Louise D; Lendl, Monika; McCormac, James; Bryant, Edward M; Acton, Jack S; Anderson, David R; Belardi, Claudia; Bouchy, François; Burleigh, Matthew R; Cameron, Andrew Collier; Casewell, Sarah L; Chaushev, Alexander; Goad, Michael R; Günther, Maximilian N; Hellier, Coel; Jackman, James A G; Jenkins, James S; Moyano, Maximiliano; Pollacco, Don; Raynard, Liam; Smith, Alexis M S; Tilbrook, Rosanna H; Turner, Oliver; Udry, Stéphane; West, Richard G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 491:Issue 2(2020)
• Page Start: 1548
• Page End: 1553
• Publication Date: 2019-11-19
• Subjects: binaries: eclipsing; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz3212
• Languages: English
• ISSNs: 0035-8711

Abstract

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 ( T ma g = 10.23, T eff = 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 M 2 = 0.148 ± 0.003 M⊙, indicating this system is an F–M eclipsing binary. The radius of the M-dwarf companion is R 2 = 0.171 ± 0.003 R⊙, making this one of the most well characterized stars in this mass regime. We find that its radius is 2.3σ lower than expected from stellar evolution models.