Neat article on further uses of Hubble that seems to keep delivering interesting results decades after the planned lifespan.
Reading, did not realize the population densities of stars in Andromeda were so heavily skewed toward Giant Branch stars (AGB, RGB). Order of magnitude or larger from what it looks like 10^0 densities vs 10^-1 densities.
[1] Image Link of Full Composite, PHAST Survey is left side. Prior PHAT survey is right side. (16 MB) https://assets.science.nasa.gov/content/dam/science/missions...
[2] Article on The Astrophysical Journal, PHAST. The Panchromatic Hubble Andromeda Southern Treasury. I. Ultraviolet and Optical Photometry of over 90 Million Stars in M31, https://iopscience.iop.org/article/10.3847/1538-4357/ad7e2b
[3] PDF Link, Page 24 and 25 have some pretty neat general survey population imagery for the entire galaxy (PHAT + PHAST combined) in the Red Giant Branch (RGB), Asymptotic Giant Branch (AGB), Young Helium Burning (HeB), and Main Sequence (MS) populations along with UV and IR imagery. https://iopscience.iop.org/article/10.3847/1538-4357/ad7e2b/...