The distance to the Pleiades from orbital solution of the double-lined eclipsing binary HD 23642

Abstract

Combining precise B, V photometry and radial velocities, we have been able to derive a firm orbital solution and accurate physical parameters for the newly discovered eclipsing binary HD 23642 in the Pleiades open cluster. The resulting distance to the binary and therefore to the cluster is 132 ± 2 pc. This closely confirms the distance modulus obtained by classical main sequence fitting methods (m - M = 5.60 or 132 pc), moving cluster techniques and the astrometric orbit of Atlas. This is the first time the distance to a member of the Pleiades is derived by orbital solution of a double-lined eclipsing binary, and it is intended to contribute to the ongoing discussion about the discordant Hipparcos distance to the cluster.