Moving to longer wavelengths, the spiral arms and star-forming regions in M81 are less prominent than in visible light. The image in this composite based on data from 1.2-2.2 microns is thus dominated by the central bulge and the old disk stars. The spiral structure is muted but still traceable, and the old redder arms don't quite match the locations of the star-forming regions.
This Atlas Image was obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and the NSF. The original JPEG version may be found in the 2MASSier Gallery.
Last changes: August 2000