Hello, all you Young Massive Compact Cluster aficionados,
Here is a paper giving individual stellar photometry for the stars in some particularly-massive (100,000 solar masses and more) star clusters in the galaxies NGC 1705, NGC 1313, Messier 83, NGC 7793, and NGC 1569.
http://arxiv.org/pdf/1106.4560v1.pdf
Studying individual stars within star clusters, in galaxies out to a distance of 16 million light years, is a very hard thing to do, even when using the Hubble Space Telescope.......0.05 arcsecond angular resolution is just barely good enough to make a start on such a project!
In observational studies of extragalactic star clusters, 0.05 arcseconds has to be regarded as extremely poor angular resolution.......
Each pixel of the detector corresponds to about 3 light years in a galaxy that is at a distance of 13 million light years, so it is hard to understand how these authors could be sure that they are detecting individual stars, without contamination from other stars......therefore I do have very strong doubts about the truth of this paper.