During the first few nights following its discovery, we observed the interstellar Ca II and Na I lines towards supernova 1993J at high spectral resolution (full width half maximum (FWHM) approximately 5-6 km/s) with the William Herschel Telescope at La Palma. We find a crowd of absorption components in the radial-velocity range -135 km/s less than

The rapidly variable Seyfert 1 galaxy NGC 4151 will be the subject of an intensive monitoring campaign with IUE, Rosat, GRO, ASCA and ground-based telescopes in December 1993. We will report preliminary results of 9.3 days of continuous monitoring with IUE, at a sampling rate of once every ~ 80 min, an order of magnitude faster than that achieved

IAUC 5907 available at Central Bureau for Astronomical Telegrams.

IAUC 5901 available at Central Bureau for Astronomical Telegrams.

The International Research on the Interior of the Sun (IRIS) helioseismometer measures the full disk line of sight velocity of the Sun. In fact, it makes a photometric mesurement using two monochromatic spectral windows located on the wings of the D1 solar line. This is a non-linear measurement. Before a scientific exploitation of the IRIS data

EN ESTE TRABAJO SE PRESENTAN LOS RESULTADOS DEL CARTOGRAFIADO DE 225 GRADOS 2 DEL PLANO GALACTICO EN 2.2 MICRAS. ESTOS MUESTRAN LA EXISTENCIA DE UNA GRAN CONCENTRACION DE ESTRELLAS BRILLANTES EN EL CENTRO GALACTICO CON UN RADIO DE 500 PC, QUE SE HA DENOMINADO BULBO INTERNO. SU FUNCION DE LUMINOSIDAD NO TIENE UNA FORMA SUAVE, SINO QUE ESTA DOMINADA