Abstract

Recent (< 0.5 Gyr) star formation histories have a large impact on the observable properties of galaxies. The HST has allowed us to construct spatially resolved star formation histories of nearby (D < 4 Mpc) galaxies with a time resolution of roughly 30 Myr over the last 500 Myr. These observations allow us to directly observe the strength and spatial relationships of the recent star formation in these galaxies. We can study the impact of recent star formation on the ISM . In the case of the dwarf galaxy Holmberg II, it appears that most of the holes in the ISM are caused by recent star formation, although not all recent star formation results in the production of an HI hole. We can also study the fraction of stars that are made in episodic bursts and characterize the duration and spatial extents of these bursts. >From a study of prototype dwarf starburst galaxies we find that the durations of the starbursts are in excess of 100 Myr, and that the star formation in the burst is distributed across the galaxies. It is also interesting to compare the star formation histories as embedded in the resolved stellar populations with the star formation rate indicators available from H-alpha, UV, and IR observations.