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We present V-band CCD photometry, UBVRI photopolarimetry, and near simultaneous JHK photometry of 3C 345 during a renewed outburst in spring of 1992, which reached maximum at the end of April. The observations also show a large and variable polarization. There are very large variations in the position angle, unlike in previously published

It is shown that supernova explosions inside wind-driven cavities created by progenitors moving across the ambient medium result in a large diversity of remnant structures. In particular, barrel-like remnants can be explained as a result of an off-centered explosion within an almost spherical cavity, whereas explosions in strongly elongated

The Department of Detectors of the Instituto de Astrofisica de Canarias, Spain is developing a data acquisition system (DAS) for an infrared camera based in a 256 X 256 InSb detector. The camera is going to work from 1 to 5 microns wavelength, with a scale on the sky of 0.5 arcsec per pixel, and will be installed as a common user instrument at the

The H-alpha emission star BD + 24 deg 676, formerly classified as a T Tauri star and more recently as a Herbig Ae star, has been observed at moderately high resolution in the red spectral region. The main results are: the metallic lines over the wavelength range 6400-6750 A have equivalent widths comparable to early G stars; the radial velocity is

A NLTE-analysis is presented of high S/N spectra of the optical component of the standard massive X-ray binary Vela X-1. In combination with the orbital parameters we conclude that the optical star is highly helium enriched and is significantly overluminous compared to standard evolutionary tracks of massive accretion stars. We then propose a new