The authors report the results of a deep imaging study of the nearby irregular galaxy GR8 using the Wide-Field Camera on the Hubble Space Telescope. These data enable them to perform photometry on stars as faint as R ≡ 24.5 with spatial resolution superior to ground-based observations. Color-magnitude diagrams in the "BVR" filters are presented and compared with cluster isochrones and evolutionary tracks for massive stars of very low metallicity. The authors conclude that the star formation history of GR8 during the past 109years resembles a "wave" progressing from the NE to the SW parts of the galaxy, as opposed to a single starburst event.
Revista Mexicana de Astronomia y Astrofisica
- Pub Date:
- November 1993
- Irregular Galaxies: Star Formation;
- Irregular Galaxies: C-M Diagrams