WFPC2 OBSERVATIONS OF THE GLOBULAR CLUSTER-M30

We describe images of the center of the dense globular cluster M30 (NGC 7099) obtained with the Hubble Space Telescope Wide Field/Planetary Camera 2. Data taken in the F336W, F439W, and F555W filters (approximately U, B, and V) yield a color-magnitude diagram with photometric errors of 1 sigma = 0.05 mag for stars with V < 17.5, and 1 sigma approximately 0.1 mag at V = 20, which is 1.5 mag fainter than the main-sequence turnoff. Simulations show that the star identifications are essentially complete for stars with V < 19.5, even in the densest regions of the cluster. The projected radial distribution of stars can be represented by a power law distribution: N(r) approximately r(alpha), with slope alpha = -0.4 +/- 0.15, into radii less than 0''.4 (0.015 pc). The radial profile is also consistent with a flat core of any radius smaller than approximately 1''.5 (0.05 pc), but inconsistent with any core radius larger than 2''.5 (0.09 pc). A total of 30 blue straggler candidates within 20'' of the cluster center have been identified from the three-color data. Their radial distribution is strongly centrally concentrated when compared to the horizontal branch, red giant branch, or main-sequence stars in the cluster. The abundance of blue stragglers (relative to red giants and subgiants) within r less-than-or-similar-to 20'' of the center of M30 is f(BS) = 0.19 +/- 0.04, about twice as high as in other dense clusters.