The Binary and Alternative Stellar Evolution Pathway Populations of the Open Cluster NGC 2506

NGC 2506 is a rich, intermediate-age, metal-poor open cluster. Its unique characteristics has made it the target of many studies, but several aspects remain under-studied, including the cluster’s binary population and alternative stellar evolution pathway populations, such as its 14 blue stragglers. This work presents the results of the WIYN Open Cluster Study radial-velocity survey of stars in the NGC 2506 field. We have made 14,000 spectroscopic observations of stars brighter than Gaia G magnitude of 17 over 41 years. Our observations include all six-dimensional members brighter than 15.5 in G magnitude, which includes NGC 2506’s upper main sequence and giants. We report the cluster’s velocity dispersion and virial mass, along with the hard-binary fraction, the mass segregation, and the period-eccentricity distribution of member binaries. We also present the orbits of binary blue and yellow stragglers and possible formation histories of each. This work was supported by the National Science Foundation through award NSF AST-1714506, the Wisconsin Alumni Research Fund, and the Wisconsin Space Grant Consortium.