Keele Research Repository

Light travel time considerations are applied to the development of the infra-red flux from a cloud of dust grains surrounding a variable cosmic source of heating radiation. The properties of individual grains are explored, and the equation of radiative transfer is solved for the case of a spherically symmetric thermal source observed at a large distance. Models of specific novae are developed from the standpoint of grains existing prior to nova outburst. The situation in which a variable primary source is surrounded by a disc of dust grains is explored, as is that in which an expanding central cavity is formed by grain evaporation. In both cases qualitative comparisons are made with observations of cosmic sources of variable thermal emission from dust grains.