OIR Research: M31 - The Great Galaxy in Andromeda
 The Great Galaxy in Andromeda (also known as Messier 31, or M31) is the nearest large galaxy to our own Milky Way. New mid-infrared observations made with the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS) aboard the Spitzer Space Telescope show that M31 looks dramatically different in the infrared than it does at visible wavelengths. As the image at right shows, its appearance is different even in the 4 mid-infrared bands of IRAC. The mid-infrared data have made it possible to measure precisely the structure of Messier 31 -- including the dramatic rings seen quite clearly at 8 microns -- and its star formation rate.


Project Links

Hectospec Studies of Stars, Clusters HII regions and PNe in M31


Scientific Publications

  • Dusty Waves on a Starry Sea: The Mid-Infrared View of M31 .pdf

  • An almost head-on collision as the origin of two off-centre rings in the Andromeda galaxy .pdf

  • Spitzer MIPS Infrared Imaging of M31: Further Evidence for a Spiral-Ring Composite Structure .pdf


    Infrared Array Camera on the Spitzer Space Telescope


    Matthew Ashby, Pauline Barmby, Nelson Caldwell, Giovanni Fazio, John Huchra, Michael Pahre, Anil Seth, Steve Willner


    Messier 31 as seen by Spitzer's Infrared Array Camera. Press release ...


    Section Photo