ULTRAVIOLET IMAGING TELESCOPE - GLOBULAR-CLUSTERS IN M31

Two 40' fields of M31 observed with the Ultraviolet Imaging Telescope (UIT) during the Astro-1 mission in 1990 December are searched for known globular clusters. The flux of 20 clusters in the nucleus field and 23 clusters in the disk field are measured in a near ultraviolet (NUV approximately 2500 angstrom) bandpass. In the far-ultraviolet (FUV approximately 1500 angstrom), only four clusters are detected with certainty, and six others are possible detections. The NUV photometry of the M31 globulars that are detected by UIT do not have a UV excess in comparison to their Galactic counterparts. The spectral energy distributions of the globular clusters from the NUV to V fall within the range of predictions of the Buzzoni models for a 15 Gyr old population. However, two of the three classical globular clusters with red NUV and visible colors that are detected in the FUV have a ''UV upturn'' with fluxes that are greater in the FUV than in the NUV. The other seven FUV detections have optical colors that are too blue for classical globular clusters and are probably the nuclei of compact OB associations.