Diagnostics of very early stages of the classical nova explosion by the modeling of its X-ray emission

Abstract

We present a spherically symmetric model of the interaction of classical nova ejecta with the matter of the companion star stellar wind. We compare its predictions with the data of observations of the unusual bright X-ray transient CI Cam and demonstrate that the outburst in 1998 can be explained as the X-ray emission at early stages of the classical nova explosion in the binary system. The X-ray outburst was observed almost immediately after the start of the motion of the ejecta (within 0.1-0.5 days) which give us the possibility to constrain two parameters of the explosions - the velocity and the mass of the ejecta. We show that the ejecta velocity was ∼2700 km/s and remained at this value over ∼2 day after the beginning of the explosion, that indicates the presence of the external forces acting on the ejecta. The mass of the ejecta was ∼ 10-7 - 10-6M⊙.