A New Study of the Open Cluster Stock 1

Studies of star clusters provide important information relating to the structure and history of our galaxy. While there are many clusters that are well studied, there remain some which have yet to be thoroughly investigated. There are even a few stellar groupings that have been suggested to be clusters but for which a physical association of the stars has yet to be confirmed. This thesis reports the results of a new study of the possible cluster Stock 1. Accurate J2000 positions for the stars were determined using the USNO A-2.0 Digital Sky Survey catalog and cross identifications determined using SIMBAD. CCD observations were used to obtain new BVRI photometry for 150 of the 158 stars listed as possible members of this cluster. The new data have been compared to previous photometry and transformation equations derived for the photographic photometry of Stock (1956) and Spalding (1979). Color- magnitude and color-color diagrams from the photometry and any available spectral types and proper motions were used to separate cluster members from non-members. The data indicate that Stock 1 is indeed a physical cluster with an interstellar reddening of E(B-V) = 0.15 and and distance modulus of Vo - Mv = 7.5.