We have monitored the X-ray source X-Per (4U 0352+30) on 31 August, 1979 through aU filter for about 1.5 hr using 102-cm telescope of Kavalur observatory. During this period intensity of X-Per fluctuated for some time, on ...

The colour differences between the star and the associated reflection nebula and polarization caused by core mantle grains and mixture of grains have been given. They are based on homogeneous plane-parallel slab-model of ...

Photometry in the O I 7774 A line and the uvbybeta system is presented for a group of high Galactic latitude F-type luminosity type I stars. The results indicate that the candidates are high gravity near solar Fe/H abundance ...