Turns out, getting slammed by a supernova can make you collapse. If you're a cometary globule.

There is a type of cloud in space called a cometary globule — a blob of dense gas and dust, usually a light year or so across, with a long tail of material that can stream for several light years.

They're usually what are called a secondary star forming feature. If you have some huge gas cloud dozens of light years across, it can form thousands of stars, some of which are massive and terribly luminous. A dense clot of gas and dust nearby will face an onslaught of high-energy ultraviolet light f...