Presentation #201.06 in the session Stars, Cool Dwarfs, Brown Dwarfs I.
Berkeley 50, also categorized as IC 1310, is a poorly studied star cluster. What brought our attention to this star cluster was the suggestion by Lowell astronomer Brian Skiff that a very red star in the center might be a red supergiant (RSG), which we quickly confirmed spectroscopically. To determine the membership of the stars in the cluster, we used proper motions from Gaia. Using images taken by Lowell astronomer Dr. Deidre Hunter, we did UBV photometry of the cluster members. Using the 4.3-meter Lowell Discovery Telescope, we used the DeVeny spectrograph to gather optical spectra of the 16 brightest member stars. We classified the stars as B-type dwarfs, with the exception of the RSG. The spectra also allowed us to determine the reddening, with an E(B-V)=0.9 mag. Gaia parallaxes of the spectroscopically confirmed members indicate a distance of 3.8 kpc. Using the distance and the reddening, we determined the intrinsic colors and absolute magnitudes of the members that lacked spectroscopy. From there, we were able to find the effective temperatures and the luminosities of all the known members in order to produce an HRD. We then compared the stars on the HRD to evolutionary tracks. As expected, we find that the RSG is the most luminous (and presumably most massive) star in this young cluster.