Gaia 8: Discovery of a star cluster containing beta Lyrae -- and of a larger old (extinct) star formation complex surrounding it

Abstract

Aims: To try and clarify whether there are stars in the neighbourhood of $\beta$ Lyrae which are physically connected to the famous prototype eclipsing binary. Methods: Scrutinize the astrometric and photometric data (from Hipparcos and Gaia DR2) of stars in a limited sky field around $\beta$~Lyrae. Results: A star cluster of about 100 members is discovered, nicely centered on $\beta$~Lyrae in 5 dimensions. There are clear indications that the newly discovered cluster belongs to a larger old (extinct) star formation complex, including two already known star clusters and an extended strewn field of stars at practically the same distance and space velocity.} Conclusions: This discovery opens up the possibility of determining a precise distance and a precise age for $\beta$ Lyrae, using the combined properties of the cluster members. This in turn may provide an important asset for an improved astrophysical interpretation of the model binary $\beta$ Lyrae and its kin. --- The larger old star formation complex is of scientific interest in its own right.