We have carried out quantitative observations of the vector magnetic field during the emergence of three small bipolar active regions in June, 1992, July 1993, and September 1994 using the Advanced Stokes Polarimeter (ASP). The region of horizontal magnetic field at the actual site of emergence is always characterized by low magnetic field strength

Spectroscopic observations for the full sample of Hα emission-line galaxy candidates (ELGs) from the Universidad Complutense de Madrid objective-prism survey Lists 1 and 2 have been obtained in order to investigate fully the properties of the survey constituents as well as the selection characteristics and completeness limits of the survey itself

We have obtained for the first time 2.10 - 2.45 micron infrared spectra of soft X-ray transient V404 Cygni. We determine a 95 percent confidence upper limit to the fraction of light arising from the accretion disc of 14 percent. The effect this has on the mass of the compact object, determined from modelling the infrared ellipsoidal variations, is

According to unified schemes for blazars, BL Lac objects are dominated by relativistic jets pointing along the line of sight. Their plane-of-the-sky counterparts are likely to be low-luminosity radio galaxies, which are generally luminous ellipticals that lie preferentially in clusters of galaxies. As part of a test of unification, and in order to

The differences between observed solar p-mode frequencies and the frequencies of a reference model can be inverted to infer the structure of the Sun using a variety of linear inversion techniques. However, it is well known that the adiabatic description, which is often employed in frequency calculations, breaks down in the outermost layers of the

EL NUCLEO SOLAR, DONDE SE GENERA LA ENERGIA, ES LA REGION MAS DESCONOCIDA DEL SOL. LOS MODOS PROPIOS DE OSCILACION DE ORIGEN GRAVITATORIO (MODOS-G), ES LA TECNICA POTENCIALMENTE MAS ADECUADA PARA ESTUDIAR ESTA ZONA DEL SOL. SIN EMBARGO, DEBIDO A LA BAJA AMPLITUD DE ESTOS MODOS Y AL NIVEL DE RUIDO TANTO SOLAR COMO ATMOSFERICO, HA SIDO IMPOSIBLE SU