HST PHAT wide image of M31
This image from Hubble spans 7,900 light-years and reveals M31’s crowded central region. The bright area to the right of the center is a grouping of stars nestled around the galaxy’s black hole. The blue dots sprinkled throughout the image are ultra-blue stars that have prematurely cast off their outer layers of material, exposing their extremely hot cores.
Credits: NASA, ESA and B. Williams and J. Dalcanton (University of Washington, Seattle)