Thanks for the reference, Robert. I use the Harris catalog to look up data on GCs I observe, e.g. HB magnitude to determine if the same-magnitude specks I see are really cluster members, and extinction to explain why a large-diameter GC in the eyepiece is so faint in my eye. N6366, 5466, 6380, & 6256 are so reddened they have the curious property of resolving into individual stars at small exit pupils, while losing their glow completely. N5053's size, absolute magnitude, and HB magnitude is not much different than nearby M53's, yet it can be impossible in any but the clearest air (in scopes that I have, anyway) while M53 is easily resolved.
The Harris catalog provides much data, but no images or CMDs. I fill in that info using
Marco Castellani's website. He really keeps it up to date: little-visited GCs like te Djorgovskis and Haute Province 1 are there. I'm impressed by how many 'amateurs' and semi-pros go to such enormous effort to collect and update info that very few will use on serious projects. Unsung heros, the whole lot.
Re Dr. Freeman and his plans to do astroseismology on Galactic bulge stars,
this paper just showed up on arXiv to demonstrate where Dr. Freeman's info might shed light (literally) on some problem areas. The 'boxy bulge' has had astronomers devising explanations for quite awhile now. The current one is two distinct disrupted dwarfs that came in from mid latitudes above the galactic plane about a Gyr apart. I still wonder how Dr. Freeman and associates can weed out the signal-to-noise chatter from atmospheric scintillation close by and the myriad filaments of gas and dust lying between us and the bulge. With metallicities, filtration is affected similarly across the spectrum, but I wonder how reliable an astroseismic signal will be when so many waveforms from so many stars are so tightly packed across a box of even a few arcsecs.
Thanks again for the tips & links. We're all grateful for the many references you provide. =Dana