EXOSAT observations of X-rays from classical novae during the outburst stage.

Abstract

Soft X-ray light curves of the classical novae Nova Muscae 1983 and Nova Vulpeculae 1984 No. 1 and No. 2 from optical maximum to about 900 days after maximum were sampled with the Exosat satellite, and the implications of the results for models of nova outbursts are considered. The observations seem best explained by the constant bolometric luminosity model of a hot white dwarf remnant. A constraint of 2-3 years is placed on the lifetime of the white dwarf remnant in Nova Muscae 1983, leading to the conclusion that the burned envelope mass should be of the order 10 to the -6th solar. The maximum temperature of the white dwarf remnant is between 200,000 and 400,000 K. A remnant evolving like the central star of a planetary nebula, with core mass of 0.8-0.9 solar, core luminosity of about 20,000 solar, and envelope mass of 10 to the -6th solar, can explain the general characteristics of the X-ray measurements for Nova Muscae 1983.