We present the first observational evidence for a collimated jet in a short-period cataclysmic variable system: the recurrent nova T Pyxidis. Optical spectra show bipolar components of H alpha with velocities ~1400 km s-1, very similar to those observed in the supersoft X-ray sources and in SS 433. We argue that a key ingredient of the formation of

In this paper we report CCD photometry in broad band B, R, and I colors, as well as in the Hα, for a sample of eight HII galaxies with strong radio emission. In addition, we present new radio continuum observations in the frequency range between 8 and 15GHz. For seven of these galaxies, previous radio continuum observations have been reported by

The Iris network for helioseismology has operated since 1989. We present tables of solar p-mode frequencies for observations taken during the four summer seasons from 1989 to 1992. This analysis uses the technique of maximum likelihood fitting and a χ_2_^2^ model for the probability density function of the spectrum. The simultaneous fitting of odd

EN ESTA TESIS PRESENTAMOS LA BUSQUEDA, DETECCION Y CARACTERIZACION DE LAS ENANAS MARRONES EN EL CUMULO ABIERTO JOVEN DE LAS PLEYADES. PARA ELLO HEMOS REALIZADO DOS EXPLORACIONES FOTOMETRICAS CCD EN LOS FILTROS RI E IZ QUE HAN CUBIERTO 0.16 GRADOS 2 Y 1 GRADO 2 EN EL CENTRO DEL CUMULO, Y ALCANZADO MAGNITUDES LIMITE I= 21.0 Y 22.2, RESPECTIVAMENTE

A survey of interstellar Na I D1 and D2 absorption features found in the spectra of 31 early-type stars in the first and fourth Galactic quadrants reveals a new picture of the large-scale kinematics of interstellar gas in the vicinity of the Sun. While absorption features found in the spectra of stars in the fourth Galactic quadrant show the gas

We have obtained simultaneous two-dimensional spectroscopy of the Ca II triplet lines in the central 24" x 20" of NGC 1068, using an optical fiber system. The stellar velocity field derived from these data shows a kinematic off-centering between the inner (r 3") and outer (r > 5") regions, indicative of a nonsymmetric gravitational potential. Both