Two years after its outburst in 1989, the William Herschel Telescope has been used to find absorption features in V404 Cyg characteristic of a late G or early K star with a radial velocity curve of amplitude 211 +/- 4 km/s and period 6.473 +/- 0.001 days. The deduced mass function of 6.26 +/- 0.31 solar masses is a firm lower limit to the mass of

Results of radio continuum and optical emission-line observations of the type 1 Seyfert galaxy NGC 3516 are presented. The radio maps reveal an elongated one-sided curved structure, which comprises a series of small-scale 'blobs' and extends up to 4 kpc from the nucleus. This radio structure is aligned and cospatial with one side of the double

The present volume on stellar formation discusses basic physical principles relevant to such processes, regions of recent star formation, galaxy formation and evolution, and the history of star formation in galaxies. Also discussed are OB associations and superassociations, triggered star formations, violent star formation in merging galaxies, and

Abstract image available at: http://cdsads.u-strasbg.fr/abs/1992SoPh..137....1S

Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain|IAC

Six CCD frames for two fields in the area of the rich, presumably old, and unstudied open cluster IC 1311 have been obtained in the BVR bands. The photometric analysis leads to an estimated age of between 1 Gyr (standard models) and 2 Gyr (overshooting models), placing the cluster at a distance of about 4.8 kpc from the sun. Comparison of the