K-band & smm light curves of the protostar HOPS 373

In our James Clerk Maxwell Telescope (JCMT) Transient Monitoring Survey, we discovered that a young binary protostar, HOPS373, is undergoing a modest 30% brightness increase at 850um, caused by a factor of 1.8-3.3 enhancement in the accretion rate. The initial burst occurred over a few months, with a sharp rise and then a shallower decay.

A second rise occurred soon after the decay, and the source is still bright one year later. The mid-IR emission, the small-scale CO outflow mapped with ALMA, and the location of variable maser emission indicate that the variability is associated with the SW component. The near-IR and NEOWISE W1 and W2 emission is located along the blueshifted CO outflow, spatially offset by ~3 to 4" from the SW component.