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

We evaluate the stratification of acoustic oscillations in the solar photosphere in both the Lagrangian (comoving) frame of reference and the Eulerian (inertial) frame of reference, from a temporal sequence of model atmospheres in an optical depth scale obtained after a quasi-non-LTE inversion of the radiative transfer equation applied to spectral

The turbulent convection zone is now considered as the only known source of the excitation of p-modes in the Sun. In Perez and Roca Cortes (1999) an analysis was made of the data set available to date of GOLF aboard SOHO (before SOHO loss), checking that the energy distribution of the acoustic modes is of a Boltzmann type. At present we have a new