Comparing Ultraviolet and H alpha Star Formation Rates
  We have used a sample of 43 star-forming galaxies imaged in the far-ultraviolet (FUV) by the UIT supplemented with 33 galaxies observed by FAUST, to explore the consistency of UV and H alpha derived star formation rates (SFRs). We find, even before correction for dust, that UV and H alpha SFRs are quantitatively consistent for low-luminosity galaxies, and that higher luminosity galaxies have H alpha SFRs a factor of 1.5 higher than their UV SFRs: this reflects the influence of dust. Our results are consistent with a scenario where the UV dust extinction is a factor of less than 2 larger than the H alpha dust extinction in a given galaxy, and that there is over a 4 magnitude range of H alpha dust extinctions which correlate loosely with galaxy luminosity such that low luminosity galaxies tend to have lower extinctions than their higher luminosity counterparts. 
Eric F. Bell and Robert C. Kennicutt Jr. (Steward Observatory)