THEORETICAL LIGHT-CURVE FOR THE RECURRENT NOVA U-SCORPII

Sequences of steady mass loss and static solutions are constructed for the envelopes on a 1.377 M⊙ white dwarf as models of the decay phase of novae. The envelopes are assumed to have a uniform chemical composition with X = 0.73, 0.33, 0.11, and 0.05 and Z = 0.02 and 0.03 for hydrogen and heavy elements by weight, respectively. An excellent agreement with the observed light curve is obtained by the hydrogen deficient models of X < 0.33, which is consistent with the observed helium enrichment. The distance to U Sco is obtained, from the comparison between the theoretical and observed visual magnitude, to be 5.2 kpc for the model X = 0.11 and the permitted range is 3.3 < D < 8.6 kpc.