From observations of almost 500 red giant branch stars in 29 Galactic open and globular clusters, we have investigated the behavior of the infrared Ca II triplet (8498, 8542, and 8662 Å) in the age range 13 Gyr

We present subarcsecond resolution mid-infrared (mid-IR) photometry in the wavelength range from 8 to 20 μm of 18 Seyfert galaxies, reporting high spatial resolution nuclear fluxes for the entire sample. We construct spectral energy distributions (SEDs) that the active galactic nucleus (AGN) dominates, relatively uncontaminated by starlight, adding

We report on time series Hα profiles of the late B-type supergiant Rigel (beta Orionis A). Our observations indicate the presence of variable and asymmetric outflows and infalls of matter. We have recorded a blueshifted high-velocity absorption component in Hα almost simultaneously with Kaufer et al. The final part of this extraordinary event has

Eight low-resolution near-infrared spectra (0.8-2.4 μm) of 32522 Thereus were obtained on 2002 August 28 from 0:30 to 5:30 UT, covering more than half of its rotation period, with the 3.56 m Telescopio Nazionale Galileo (TNG) at El Roque de los Muchachos Observatory (ORM, Canary Islands, Spain). All the spectra are red, probably due to a mantle of

A promising approach to decrease the uncertainties in the initial--final mass relationship, which is still poorly constrained, is to study white dwarfs for which external constraints are available, for instance, white dwarfs in common proper motion pairs (CPMPs). Important information of the white dwarf can be inferred from the study of the

The Isaac Newton Telescope (INT) Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800-deg2 CCD survey of the northern Milky Way spanning the latitude range -5° b + 5° and reaching down to r'~= 20 (10σ). Representative observations and an assessment of point-source data from IPHAS, now underway, are presented. The data obtained