Add *Milky Way Globular Clusters* by Harris, W.E. et al

[scottstirling]

Catalog started in 1997, updated and maintained with a few more entries in 2010:

https://spider.seds.org/spider/MWGC/mwgc.html
https://physics.mcmaster.ca/~harris/mwgc.dat

Size: 157 entries

[scottstirling]

The apparent dimensions of the globs here are defined in terms of core and half light core brightness, which will not yield correct (they'll be too small) diameter dimensions for visual angular magnitude of each cluster. I think I have a solution but noting this as the reason for delay.