M31 mosaic, inset in ground-based image to show what part of the galaxy Hubble has imaged.

M31-mosaic-with-groundbased-image

Hubble’s M31 mosaic image, taken by the Panchromatic Hubble Andromeda Treasury (PHAT) program, is shown in context with a ground-based image of the entire galaxy. Despite the size of Hubble’s massive mosaic, it does not span even half of the galaxy.

Credits: NASA, ESA and Z. Levay (STScI/AURA); PHAT Mosaic: NASA, ESA, J. Dalcanton, B.F. Williams, L.C. Johnson (University of Washington), the PHAT team and R. Gendler; Ground-based Background Image of M31 (c) 2008 R. Gendler, used with permission