N. I. Shakura

On the calculation of the vertical structure of accretion discs

Abstract A new method of calculating the vertical structure of optically thick accretion discs is proposed. In order to solve the problem, a search for the eigenvalues of the dimensionless parameters for a set of four ordinary differential equations with definite boundary conditions was undertaken. It is shown that the vertical structure of optically thick accretion discs can be satisfactorily described by polytropic models.

UBVR colours of accretion disks and power-law sources of radiation with interstellar reddening

Abstract The (U–B), (B–V) and (V–R) colour indexes from accretion disks, and sources with power-law spectra, are calculated. They take into account interstellar extinction, in detail. Results are given on two-colour diagrams (U–B)-(B–V) and (B–V)−(V–R). Applications to Nova Vul 1988 and A0620–00 are discussed shortly.

Polarization of intrinsic radiation of tidally distorted stars with electron-scattering atmospheres. I: The case of conservative scattering

The variable linear polarization of the intrinsic radiation emitted by tidally distorted stars was computed with approximation of pure electron or Rayleigh scattering in the atmospheres. A precise form of the equipotential surfaces within the binary system Roche model, which approximates the form of the star surface, was taken into account. Calculations were made using the Sobolev (1949) and Chandrasekhar (1950) solutions of transport equations for an optically thick medium without true absorption. The behaviour of the Stokes polarization parametersQ/I andU/I and the dependence of these on the parameters of the (Q×U) plane. The possibility of establishing the inclination anglei of the system and the degree of filling the Roche-lobe μ from these curves is discussed. The conclusion is drawn that the amplitude of polarization variations is small, not generally exceeding 0.4%; however, in a number of cases it remains at the observable level.