ALMA finds compact massive-star core in the Dragon Cloud

Object C2c1a in the Dragon Cloud, about 16,300 light-years away, resolves into a single compact source roughly 87 AU across with a brightness temperature of ~40 K, embedded in a reservoir of about 110 solar masses of gas and dust. No hot gas or strong outflows were detected, and the core's mass is estimated at 2 to 30 solar masses.

• Compact source C2c1a(a) has a radius of about 87 AU, below the 175 AU resolution limit
• Core brightness temperature is ~40 K versus ~10 K for the surrounding gas
• Surrounding reservoir holds up to 110 solar masses of gas and dust at ~10,000 AU
• Core mass remains uncertain, estimated between 2 and 30 solar masses