SWIFT/UVOT STUDY OF STELLAR POPULATIONS IN STAR CLUSTERS

WE PROPOSE TO ANALYZE ARCHIVAL ULTRAVIOLET IMAGES PRIMARILY FROM SWIFT/UVOT OF A REPRESENTATIVE SAMPLE OF GALACTIC OPEN CLUSTERS SPANNING A BROAD RANGE OF ASTROPHYSICAL PROPERTIES. EVALUATION OF THE CLUSTERS' UV COLOR-COLOR DIAGRAMS COLOR-MAGNITUDE DIAGRAMS AND INTEGRATED LIGHT WILL PROVIDE UNIQUE INSIGHT INTO THE UV PROPERTIES OF STELLAR POPULATIONS OF A VARIETY OF AGES AND METALLICITIES WITH CONCOMITANT INSIGHT INTO THE STELLAR POPULATIONS OF MORE DISTANT EXTRAGALACTIC OBJECTS. THIS PROGRAM WILL PRODUCE DRAMATIC IMPROVEMENT IN THE CHARACTERIZATION OF THE UV PROPERTIES OF STELLAR POPULATIONS AS WELL AS THE PROPERTIES OF THE INDIVIDUAL CLUSTERS THEMSELVES. IT WILL PROVIDE OBJECTS WITH WHICH TO CHARACTERIZE THE UV EXTINCTION PROPERTIES OF THE GALAXY. FINALLY THIS STUDY WILL PRODUCE A LIBRARY OF STELLAR POPULATIONS IN THE SWIFT/UVOT FILTERS PROVIDING AN EMPIRICAL BASELINE AGAINST WHICH TO MEASURE THEPROPERTIES OF COMPOSITE OR INTEGRATED STELLAR POPULATIONS IN MORE DISTANT EXTRAGALACTIC OBJECTS. THIS WILL PROVIDE A POWERFUL LEGACY FOR FUTURE STUDIES AND OPEN UP NEW AREAS OF INVESTIGATION FOR SWIFT/UVOT AND OTHER SPACE-BASED UV INSTRUMENTS.