Collapse of a molecular cloud core to stellar densities: the radiative
  impact of stellar core formation on the circumstellar disc
  We present results from the first three-dimensional radiation hydrodynamical
calculations to follow the collapse of a molecular cloud core beyond the
formation of the stellar core. We find the energy released by the formation of
the stellar core, within the optically-thick first hydrostatic core, is
comparable to the binding energy of the disc-like first core. This heats the
inner regions of the disc, drives a shock wave through the disc, dramatically
decreases the accretion rate on to the stellar core, and launches a temporary
bipolar outflow perpendicular to the rotation axis that travels in excess of 50
AU into the infalling envelope. This outburst may assist the young protostar in
launching a conventional magnetic jet. Furthermore, if these events are cyclic,
they may provide a mechanism for intense bursts of accretion separated by long
periods of relatively quiescent accretion which can potentially solve both the
protostellar luminosity problem and the apparent age spread of stars in young
clusters. Such outbursts may also provide a formation mechanism for the
chondrules found in meteorites, with the outflow transporting them to large
distances in the circumstellar disc.
