We report the discovery of a new two-image gravitational lens candidate. The system RX J0921+4529 contains two zs=1.66 quasars separated by 6.93" with an H-band magnitude difference of Δm=1.39. The HST NIC2 H-band images reveal an H=18.2 spiral galaxy between the quasar images, which is probably a member of a zl=0.32 X-ray cluster centered on the

Not Available

In order to investigate the oscillatory behaviour of the magnetic field in sunspots and pores, full Stokes measurements of 1.56 μm iron lines have been performed using the Tenerife Infrared Polarimeter (TIP) at the German Vacuum Tower Telescope on Tenerife. As expected, velocity oscillations have power peaks at five minutes. First results for

We present an analysis of the frequency shift and the even terms of the frequency splitting coefficients carried out using six years of LOWL data, starting in 1994. The temporal variations, and their dependences with the frequency and degree are addressed. The results are consistent with previous analysis.

Around 50 planetary nebulae (PNs) are presently known to possess ``small-scale'' low-ionization structures (LISs) located inside or outside their main nebular bodies. We consider here the different kinds of LISs (jets, jetlike systems, symmetrical and nonsymmetrical knots) and present a detailed comparison of the existing model predictions with the

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