The astrophysical importance of the negative positronium ion, detected recently in the laboratory, has been pointed out. It is found that the presence of Ps(-) ions will contribute additionally to the width of the 0.511 ...

Recently an Indian Astronomical Observatory has been set up at Hanle (32° 46 4 6 N , 78° 57 5 1 E , 4515m amsl) situated in the high altitude cold desert in the Himalayas. The Observatory has 2-m aperture optical-infrared ...

The Cousin R and I band photometric observations of ~ 13 x 13 field in the direction of M31 galaxy have been carried out during 1999-2001 to search for microlensing events using pixel technique. Here we report a microlensing-like ...

IRAS data for high-galactic-latitude F supergiants, a few luminous F-G stars, and a few peculiar (forbidden) emission-line stars reveal they have dust shells with characteristics similar to those observed in planetary ...

Kilohertz quasi-periodic brightness oscillations (kHz QPOs) observed in certain X-ray burst sources may represent Keplerian frequencies in the inner regions of the accretion disk in such systems. If this assumption is ...

Several massive young stellar objects are found from an analysis of the 12- to 100-micron flux data of IRAS sources in the region of the Cyg OB2 association. Sixty-four sources with positive spectral indices and steeply ...

Quasi-periodic pulsations with periods mostly around 13 s in the frequency range of 54-78 MHz have been observed following the first X2 flare occurring on 24 November 2000. Assuming an impulsively generated propagating MHD ...