We report the detection of the secondary star spectrum in the hard X-ray transient GRO J0422+32 during its lowest quiescent state. From the amplitude of the radial velocity curve we derive a mass function f(M)=0.85+/-0.30M_solar. We classify the companion star as type M2+/-2V which contributes 35+/-6 per cent of the total flux in the spectral range

We study the orbital properties of dumbbell galaxies which harbor twisted radio jets. Velocity and velocity dispersion profiles for four dumbbell pairs (3C66B, 3C75, 3C449, 0326+39) are presented. We analyze optical CCD images in search of isophote off-centering and large isophote twists. Combining the kinematic and isophotal information, we

IRAS 17423-1755 has been recognized as a new bipolar nebula during a multi-wavelength observational program of unidentified IRAS sources with far infrared colours similar to those of known planetary nebulae. B, V, R and Hα CCD images show a clearly marked bipolar structure with a total extension of ~11 arcsec. The spectrum of the core shows strong

We report broad-band imaging observations which reveal a circum-nuclear gas ring in NGC 4151. The ring is delineated by two arc-like features probably resulting from dust extinction of the background stellar continuum. These features are distributed along opposite quadrants of an elliptical ring which has a semi-major axis of length 1.8kpc and is

We have observed, with high spectral resolution, the BeII resonance doublet at λ 3131A in five G and K-type main-sequence stars belonging to the Hyades open cluster, as well as in four K-type probable members of the Ursa Major Group. We carried out a detailed abundance analysis via spectral synthesis fitting and studied the utility of the BeII

EK Cep is a double-lined eclipsing binary system with unique characteristics. Accurate absolute dimensions are available, a good determination of the surface lithium abundance has been made, the system is known to show apsidal motion variations, and its secondary component seems to be in the pre main sequence phase. Due to all this, it appears to