An objective of the GOLF experiment (Global Oscillations at Low Frequencies) on-board the SOHO (Solar and Heliospheric Observatory) space mission was to measure the line-of-sight component of the disk-averaged magnetic field of the Sun. In this paper, a theoretical study of this observable is presented. The newly developed techniques are tested

We continue our study of the young stellar object associated with IRAS 05327+3404. We have determined the spectral type of the central star to be K2. We show that the star is most likely seen directly, not via a reflection, and that the extinction is only A_V ~ 2.3 mag. The spectral energy distribution shows the presence of large amounts of

In response to our recent discovery of spiral arms in the accretion disc of IP Peg during rise to outburst, we have obtained time-resolved spectrophotometry of IP Peg during outburst maximum. In particular, indirect imaging of He II 4686, using Doppler tomography, shows a two-arm spiral pattern on the disc image, which confirms repeatability over

From an analysis of the spectrum (4000 Ä to 8800 Ä) of HD 101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300 Ä and 6363 Ä and [CI] 8727 Ä are detected, which indicate the presence of a very low excitation nebula. The Hα , FeII 6383 Ä, NaI D1, D2 lines and the CaII

Two-dimensional spectroscopy of the central 24^''x20^'' of the Seyfert 2 galaxy NGC 1068 has been obtained using a fiber-optic system (2D-FIS). The homogeneity, spectral coverage (~4170-5749 and 6250-9469 Å), and spatial (~0.9") and spectral resolution (~1.53 Å pixel^-1 and 2.73 Å pixel^-1) of the data make them a useful database with which to

La presencia de estructura espiral en galaxias (incluso antes de saber que las nebulosas eran objetos realmente extragalácticos) es uno de los temas que más interés ha despertado en la Astronomía. La teoría más famosa enunciada en los años 60 para explicar la presencia de esta estructura, la teoría de las ondas de densidad, no ha sido aún