This is an early release UIT image of spiral galaxy M74, taken in the UV light. This image was taken by UIT during Astro-1 and is shown here in false-color.
Ultraviolet image from the ASTRO-1 mission. In this image, the regions of star formation along the spiral arms stand out prominently because of their high UV brightness. UIT is a 38-cm f/9 Ritchey-Chretien telescope.
This image was taken at a wavelength of 2,500 angstroms.
Visible image, taken for comparison with the UV results from the ASTRO-1 mission. This is a direct CCD image of M74, obtained in October 1991 from the San Diego State University's Mount Laguna Observatory, with a 1-meter telescope. See Cornett et.al. (1994).
This image was taken in the visible V band. Both images above have the same scale. The central bulge, consisting primarily of old, red stars, dominates this ground-based image, while the above UIT image shows the patchy regions of star formation, containing young bright and hot stars, and tracing the spiral arms.
Photometric investigations in different UV bands can give information on the age and distribution of masses of young stars in M74 and other spiral galaxies.
UV and visible overlay.
Last Modification: 28 Jun 1999