We present the lithium measurements of a continuing programme of light element abundances in metal-poor stars. New equivalent widths of the Li i lambda 670.8 nm resonance line in 67 metal-poor stars covering the metallicity range -3.5

This paper shows how to generalize to non-LTE polarization transfer some operator splitting methods that were originally developed for solving unpolarized transfer problems. These are the Jacobi-based accelerated Lambda-iteration (ALI) method of Olson, Auer, & Buchler and the iterative schemes based on Gauss-Seidel and successive overrelaxation

We present echelle spectroscopy in the 3500 to 10300 Angstroms range for two positions of the galactic H ii region M17. The data have been obtained using the 2.1 m telescope at Observatorio Astronomico Nacional in San Pedro Martir, Baja California. We measure the intensities of 160 emission lines, in particular 36 permitted lines of C(+) , N(0) , N

We present a detailed study of the stellar kinematics in the barred galaxy NGC 5728 based on I-band photometry and long-slit spectroscopic observations in the region of the near-IR Ca II triplet. The analysis of the stellar line-of-sight velocity distribution (LOSVD) has revealed, in the central regions of the bar, the presence of a cold (v/sigma~2

The properties of the evolution of solar granulation have been studied using an 80 minute time series of high spatial resolution white-light images obtained with the Swedish Vacuum Solar Telescope at the Observatorio del Roque de los Muchachos, La Palma. An automatic tracking algorithm has been developed to follow the evolution of individual

Two-dimensional spectroscopy of the low-redshift active galaxy NGC 4303 obtained with the Two-Dimensional Fiber ISIS System is presented. The ionization structure and velocity field of the nuclear region of this galaxy, where a compact UV-bright spiral structure connected with the UV-bright core has been detected with the Hubble Space Telescope