Rediscussion of eclipsing binaries. Paper XVIII. The F-type system OO Pegasi

OO Peg is a detached eclipsing binary system containing two late-A-type stars in a circular orbit with a period of 2.985 d. Using published spectroscopic results and a light curve from the Transiting Exoplanet Survey Satellite (TESS) we determine their masses to be 1.69 +/- 0.09 and 1.74 +/- 0.06 Msun, and their radii to be 2.12 +/- 0.03 and 1.91 +/- 0.03 Rsun. The TESS data are of high quality, but discrepancies in the radial velocities from two sources prevent a precise mass measurement. The primary star is definitively hotter, larger and more luminous than its companion, but its mass is lower (albeit to a significance of only 1.1 sigma). Using published apparent magnitudes and temperatures, we find a distance of 238.8 +/- 6.1 pc, in agreement with the Gaia DR3 parallax. Although both components are in the delta Scuti instability strip, we find no evidence of pulsations. More extensive spectroscopy is needed to improve our understanding of the system.
Comment: Accepted for publication in The Observatory. 12 pages, 4 tables, 3 black/white figures