Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of ~90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles are reliable (1 σ uncertainty less than 0.2 mag) down to μ˜27 mag/''. Only ~10% of all galaxies have a normal

Observations are presented of high resolution interstellar Na I D and K I (lambda 7699 Angstroms) line profiles towards 7 stars in the globular cluster NGC 6541 and 3 field stars within 3° of the cluster. It is seen that the gas in this general direction (l, b ~ 350°, -11°) shows a complex structure, having the greatest number of components yet

In this timely volume, the editors present eight specially-written chapters by experts renowned for their teaching skills. The chapters show how astronomers can deduce the internal composition (density, helium abundance, etc.) and dynamical structure (rotation, sub-surface velocity fields, etc.) of the Sun through helioseismology, and how

We combine results from imaging searches for substellar objects in the σ Orionis cluster and follow-up photometric and spectroscopic observations to derive a census of the brown dwarf population in a region of 847 arcmin2. We identify 64 very low mass cluster member candidates in this region. We have available three-color (I, Z, and J) photometry

Aims:We investigate the mass function in the substellar domain down to a few Jupiter masses in the young σ Orionis open cluster (3±2 Ma, d = 360^+70_-60 pc). Methods: We have performed a deep IJ-band search, covering an area of 790 arcmin2 close to the cluster centre. This survey was complemented with an infrared follow-up in the HK_s- and Spitzer

We review different surveys, in the optical and infrared, conducted in the very young (age 1 8 Myr), nearby (d ˜ 350 pc) σ Orionis cluster aimed to characterize the substellar population. We describe spectral characteristics of very low mass stars, brown dwarfs and planetary mass objects in the cluster with spectral types from K7 to T6. We study