Infrared and radio observations of classical novae: Physical parameters and abundances in the ejecta

Infrared and radio photometric, spectroscopic, and imaging observations of classical nova explosions can be used to determine physical parameters associated with the outburst and elemental abundances in the ejecta. It is shown that some recent CO and ONeMg novae ejected shells with significantly enhanced abundances of CNO, Ne, Na, Mg, Al, Si, and S. The properties of nova dust grains are reviewed and compared to those of the grains in Interplanetary Dust Particles (IDP's) and comet comae. The possibility that classical novae may be a potential source of chemical anomalies and grains in the ISM and the primitive Solar system is considered. Future investigations of remaining unresolved issues are suggested.