2020ApJ...894...96T

We report extensive differential V-band photometry and high-resolution spectroscopy for the 1.14 day, detached, double-lined eclipsing binary BT Vul (F0+F7). Our radial-velocity monitoring and light-curve analysis lead to absolute masses and radii of M₁=1.5439±0.0098 M_☉^N and R₁=1.536±0.018 R_☉^N for the primary, and M₂=1.2196±0.0080 M_☉^N and R₂=1.151±0.029 R_☉^N for the secondary. The effective temperatures are 7270 ± 150 K and 6260 ± 180 K, respectively. Both stars are rapid rotators, and the orbit is circular. A comparison with stellar evolution models from the MESA Isochrones and Stellar Tracks series shows excellent agreement with these determinations, for a composition of [Fe/H]=+0.08 and an age of 350 Myr. The two components of BT Vul are very near the zero-age main sequence.