star-forming region

A star-forming region (SF region, stellar nursery, SFR) is a region in space where star formation is taking place, or could happen. The presence of protostars is a clear sign, as well as a dense molecular cloud, perhaps with dust, as is the presence of early-type stars which don't live long and necessarily formed recently. The term SF region is generally used for a fairly large volume that would form a number of stars, such as might result in one or more an open clusters. Sometimes such formation occurs in a long, narrow region termed a filament. The terms Bok globule and dense core refer to smaller regions presumed to be locations where one or more stars are in the process of forming.

Note: the abbreviation SFR is also used for star formation rate.