We propose two-frequency (2.3 and 8.4 GHz) monitoring of young radio supernovae in Arp 299 (NGC 3690) which
have been discovered in our previous observations of this object. To date, we have detected ve young supernovae or
supernova remnants in Source A of Arp 299, including one with a strongly inverted spectrum. In addition, a sixth
object, Source D, located about 10 00 (2 kpc) to the south had its 2.3 GHz density increase by a factor of 6
between April 2002 and April 2003; this may be a young supernova that is just transitioning to become optically
thin at low gigahertz frequencies. Our primary observational goals are to determine the spectrum and evolution
of the apparent supernovae, as well as search for new objects. This monitoring will provide information about the
supernova ages and the radio supernova rate, as well as the evolution of radio supernovae exploding in a much denser
medium than most such objects that have been monitored previously. |