Absolute Dimensions of the Unevolved F-type Eclipsing Binary BT Vulpeculae

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 and for the primary, and and 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 and an age of 350 Myr. The two components of BT Vul are very near the zero-age main sequence.