Infrared photometry of Nova Serpentis 1978

Infrared photometry of Nova Ser 1978 was obtained from 36--127 days after the discovery. A prominent dust-shell spectrum was evident in the first observations and its development was followed through maximum infrared light and early decline. The temperature of the dust shell remained between 1100 and 900 K during the observing period. This constant temperature is explained in terms of dust which condenses at a critical radius in continuously outflowing material. It is likely that the dust shell emitting the bulk of the thermal radiation is optically thin at infrared wavelengths. In terms of its dust shell parameters (mass, radius at maximum infrared light and infrared optical thickness) Nova Ser 1978 is very similar to Nova Ser 1970 and Nova Vul 1976.