The absolute visual magnitudes of two Wolf-Rayet stars HD 151932 (WN 7) and HD 152270 (WC 7+08) have been determined from their energy distributions and monochromatic magnitudes least contaminated by emission lines taking ...

The Changes in the Ca II K line profile of the F0 supergiant Canopus have been studied from the high dispersion coude spectrograms obtained since 1975. The emission in the core of the line is variable in a timescale of few ...

Calcium network diameters are shown to be smaller by 5% at solar maximum than at minimum. The average cell size at minimum is 22,115 + or - 99 km. The average size at solar maximum is 20,920 + or - 112 km, though individual ...

Photoeletric measures of emission band intensities of C2(I,O) and CN (O,O) of the coma of Comet Ikeya-Seki (1965f)are reported. The measured fluxes are utilized to determine the number of molecules of C2 and CN that ...