Complementing Space Telescopes from the Ground

Gemini North Adaptive Optics (AO) image of crowded star field in the bulge of M31. The near-infrared color composite image (J,H,K) was obtained as part of the research by Olsen et al., to study star formation histories in the disk and bulge of M31 (as described in the accompanying press release). The bright star at center is a foreground Milky Way star used as the AO guide star to sample atmospheric turbulence. The image is 20 arcseconds on a side, or roughly the angle spanned by a small grain of sand held at arm’s length.Image obtained with the Gemini North Telescope on Mauna Kea, Hawai‘i with the ALTAIR AO system built and designed by the National Research Council of Canada’s Herzberg Institute of Astrophysics.