We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant

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The authors present the results of narrow-band filter photometry of Periodic Comet Faye obtained from Estacion Astronomica "Dr. Carlos U. Cesco" of Felix Aguilar Observatory, San Juan, Argentina, in November and December 1991 using the International Halley Watch (IHW) standard filters. The production rates of CN, C2 and C3 are derived from the

The results of an intensive site testing assessment campaign, held at the Observatorio del Roque de los Muchachos (ORM) (La Palma) during four nights on July 1990 are presented and discussed. To evaluate the optical quality of an astronomical site for high angular resolution astronomy our philosophy leads us to make use of as many instruments as

EL OBJETIVO DE ESTE TRABAJO ES EL ESTUDIO DE BLAZANES Y DE QUASARES EN GENERAL, CON LA INTENCION DE ESTABLECER LAS POSIBLES SIMILITUDES Y DIFERENCIAS QUE PUEDAN CLARIFICAR LA CLASIFICACION DE ESTOS OBJETOS. CON ESTA IDEA SE HA DESARROLLADO UN IMPORTANTE PROGRAMA OBSERVACIONAL EN EL VISIBLE E INFRARROJO ESTUDIANDO LA VARIABILIDAD DE ESTOS OBJETOS

Results of a five-month campaign of optical monitoring the Seyfert 1 galaxy NGC 4593 are presented. High resolution H-alpha and H-Beta spectra and direct images in the Johnson U, B, V, R, and I bands were obtained between January and June 1990. The emission lines and the continuum showed strong variations on time scales of weeks to days. The H