We have treated formation of spectral lines in a commoving frame where photoionization is predominant over collisional processes. We have assumed that the radiation field for causing photoionization is a function of Planck ...

Observations on the pulsation pattern in the time profile of short duration solar radio bursts at decametre wavelengths are presented. The pulsations are found to be present predominantly in the saturation phase of the ...

The time-dependent interaction of the granulation velocity field with a magnetic flux tube is investigated here. It is seen that when a magnetic field line is displaced normal to itself so as to simulate thebuffeting action ...

We have obtained a simultaneous solution of the statistical equilibrium equation for a non-LTE two-level atom and the radiative transfer equation in the comoving frames by employing the angle-averaged partial frequency ...

Epsilon Aurigae is a long-period eclipsing system containing a F0 Ia supergiant and an unseen slightly less-massive secondary. A primary eclipse began in mid-1982 with the unseen companion passing in front of the supergiant. ...

IUE observations of the hydrogen-deficient irregular variable star MV Sgr obtained in June-October 1980 and November 1979 are discussed. The observations reveal a prominent 2200 A absorption feature. A value of E(B - V) = ...

Direct photographs of Comet Ikeya-Seki obtained on four consecutive days from October 29 to November 1, 1965, are used for an analysis of the multiple helical structures in the ionised tail. The formation of these structures ...