Diverse protostellar evolutionary states in the young cluster AFGL961
  We present arcsecond resolution mid-infrared and millimeter observations of
the center of the young stellar cluster AFGL961 in the Rosette molecular cloud.
Within 0.2 pc of each other, we find an early B star embedded in a dense core,
a neighboring star of similar luminosity with no millimeter counterpart, a
protostar that has cleared out a cavity in the circumcluster envelope, and two
massive, dense cores with no infrared counterparts. An outflow emanates from
one of these cores, indicating a deeply embedded protostar, but the other is
starless, bound, and appears to be collapsing. The diversity of states implies
either that protostellar evolution is faster in clusters than in isolation or
that clusters form via quasi-static rather than dynamic collapse. The existence
of a pre-stellar core at the cluster center shows that that some star formation
continues after and in close proximity to massive, ionizing stars.
