The evolution and spectra from a compact supernova remnant evolving in a high-density circumstellar medium with a density of 107cm-3 are presented. The radiation emitted by the shocked region can self-ionize the cooling shell and a large region of the surrounding medium. The resulting line ratios from the photoionized zones are similar to those

We present high spectral and spatial resolution spectroscopy of the nuclear starburst region of the galaxy NGC 253. Two slit positions, matching the major and minor axes on the galaxy, have been taken. These cover H-alpha and (N II) lines as well as the (S II) doublet. The attained resolution, together with good seeing conditions, have allowed the

The authors report photoelectric and CCD photometry of V651 Mon, the central star of the planetary nebula NGC 2346, made in April - May and November, 1992. During each of these two epochs an occultation was measured, of amplitude 0.20 and 0.35 in the observed V magnitude, in accordance with previous results. These variations may be interpreted in

UTILIZANDO ESPECTROS DE ALTA RESOLUCION (LAMDA/INCREMENTO LAMDA = 810 ELEVADO A 4) DE LA LINEA KI DE ABSORCION INTERESTELAR, SE ESTUDIAN LAS NUBES FRIAS (T = 100 K) DEL MEDIO INTERESTELAR LOCAL (MIL). SE ESTIMAN DISTANCIAS, TAMAÑOS, DENSIDADES, TEMPERATURAS Y MASAS DE LAS NUBES. UNA DE LAS NUBES, SITUADA EN PERSEO, SE ESTUDIA MAS DETALLADAMENTE CON

The velocity field of the central parts of the elliptical galaxy NGC 7626 has been mapped by obtaining high resolution curves and velocity dispersion profiles for four slit position angles along the major, minor and two intermediate photometric axes. Each rotation curve and dispersion profile shows a high level of structure. Along the major axis

We present the results of a multi-site photometric campaign to monitor T Tauri stars in the Taurus-Auriga stellar formation region. The campaign - dubbed COYOTES, for Coordinated Observations of Young Stellar ObjecTs from Earthbound Sites - yielded UBVRI magnitudes of 13 classical T Tauri stars, 10 weak-line T Tauri stars, and one suspected Ae