ALMA Spots a Nascent Stellar Monster

ALMA Spots a Nascent Stellar Monster:

"Even though it comprises over 99% of the mass of the Solar System (with Jupiter taking up most of the rest) our Sun is, in terms of the entire Milky Way, a fairly average star. There are lots of less massive stars than the Sun out there in the galaxy, as well as some real stellar monsters… and based on new observations from the Atacama Large Millimeter/submillimeter Array, there’s about to be one more."

The formation of massive stars remains, in many ways, a mystery (Beuther et al. 2007; Zinnecker & Yorke 2007). More specifically, the key question of what physical processes determine their mass accretion history is yet to be answered. On one hand, some theories predict that primordial fragmentation of globally stable molecular clouds may form compact reservoirs of gas, called cores (with sizes up to 0.1pc), from which a forming star subsequently accumulates its mass (McKee & Tan 2003; Beuther & Schilke 2004). In an alternative scenario, molecular clouds undergo global collapse (Peretto et al. 2006, 2007), gathering matter from large scales to the centre of their gravitational potential well, where cores, and protostars in them, are simultaneously growing in mass (Bonnell et al. 2004; Smith et al. 2009). Only detailed observations of individual massive star forming cloud can provide hints on which of these scenarios, if any, is most relevant.

Even though it still remains to be demonstrated that global collapse is the main process through which massive star progenitors accumulate mass, the case of SDC335 sets strong constraints on any theory of massive star formation.

'via Blog this'