H-II REGIONS IN M81 GROUP DWARF GALAXIES

Halpha images of the H II regions of five members of the M81 Group-Ho I, Ho IX, M81dA, M81dB, and IC 2574-have allowed us to calculate their present star formation rates. The H II regions of the galaxies are no rmal in both their luminosity functions, which are power laws with sha llow slopes (approximately -1.4), and in their size distributions, whi ch fit exponentials (D0 approximately 50 pc). However, we find that th ere is a wide range of star formation activity as measured by the star formation and gas depletion timescales. Present star formation activi ty ranges from essentially zero for M81dA, which has no detected H II regions, to more active galaxies, such as IC 2574. M81dB appears to be in a burst phase.