A circumstellar disk associated with a massive protostellar object

There are two competing theories to explain how high-mass stars form: either they arise from mergers of low-mass younger stellar objects or, like low-mass stars, they arise by accretion from a circumstellar disk. The latter theory gets a boost from new observations of disks of dust and molecular gas around two high-mass protostars. A 15-solar-mass protostar in the Cepheus A region, and the 7-solar-mass Becklin–Neugebauer object in the famous star-forming region in Orion appear well on the way to star formation by accretion.