SIMBAD references

We discuss the star formation history in the post-starburst galaxy NGC 1569 using colour-magnitude diagrams derived from HST WPFC images in the F555W and F785LP filters. This galaxy has experienced a global burst of star formation from 1x10⁸yr to about 4Myr ago. Evidence has been found of older episodes of star formation from 1.5Gyr to 1.5x10⁸yr ago, which rules out long quiescent phases in this galaxy. Simple calculations of the stellar energy input into the supergiant shells found in NGC 1569 suggest that the hot gas inside these structures will probably blow out of the galaxy.