Wizard Nebula

NGC 7380 in Cepheus is a young open cluster still sitting inside the cloud it formed from, the emission nebula Sh2-142, around 7,200 light-years away. Nearly all of the light comes from one source: DH Cephei, a close binary of two hot O-type stars near the centre of the cluster, whose ultraviolet output ionises the surrounding hydrogen and drives an ionisation front outward through the gas. The pointed towers that give the nebula its wizard-like silhouette are what survives that erosion — dense knots of dust and molecular gas, Bok globules and evaporating gaseous globules, each shielding a tail of material downwind of it, with new stars condensing inside some of them. Caroline Herschel found the cluster in 1787; at roughly 4 million years old it is young enough that the gas has still not been cleared away from the stars it made.