CCD monitoring of Comet Hale-Bopp (1995 O1) has been carried out on more than 50 nights using the 82cm IAC-80 Telescope at Teide Observatory (Tenerife, Spain), operated by the Instituto de Astrofísica de Canarias. A combination of deep exposures of the extended coma in BVRI (up to 2 hours total exposure in a single filter) and near nucleus imaging

We have computed limb-darkening coefficients for five commonly used near infrared photometric bands, namely R, I, J, H, and K, using the stellar atmosphere models by Kurucz (1993). Since the behaviour of the specific intensities is very dependent on the range of effective temperatures considered, we have adopted three analytical approximations to

High resolution spectroscopic observations have been obtained for the ring nebulae around the galactic Wolf-Rayet stars WR 113 (CV Ser), WR 116, WR 128 (MR 95), WR 133, WR 134 (MR 100) and WR 153 using an echelle spectrograph. Gaussian fit analysis of the emission lines has been performed to establish the dynamical classification of the objects as

The GOLF experiment on the SOHO mission aims to study the internal structure of the sun by measuring the spectrum of global oscillations in the frequency range 10-7 to 10-2 Hz. Bothp andg mode oscillations will be investigated, with the emphasis on the low order long period waves which penetrate the solar core. The instrument employs an extension

Not Available

We compare the details of the distributions of HI, Hα , and far-UV emission in the spiral arms of M81, at a resolution of about 9'' (linear resolution 150 pc at 3.7 Mpc distance). The effects of extinction on the morphology of the Hα and far-UV are shown to be essentially bi-modal, i.e. the extinction is either very small or very large. The