BL Lacertae has been the target of four observing campaigns by the Whole Earth Blazar Telescope (WEBT) collaboration. In this paper we present UBVRI light curves obtained by the WEBT from 1994 to 2002, including the last, extended BL Lac 2001 campaign. A total of about 7500 optical observations performed by 31 telescopes from Japan to Mexico have

The use of alternative energies is becoming common in many places around the world. It is envisaged that most large projects will consider the use of alternative energies in this new century. Such use or at least the attempts to use renewable energies to somewhat offset the power requirements of an ELT will be seen very positively by the general

We present the values of CN and Mg overabundances with respect to Fe, for early-type galaxies in 8 clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey (SDSS) DR1 spectroscopic database, and from WHT and CAHA observations. Abundances were derived from absorption lines and single burst population

We are carrying out a study of the physical parameters and excitation of low-ionization structures (LIS) in planetary nebulae (PNe). Since the optical morphology and kinematics of the LIS and the main components (rims, shells and haloes) of our sample were studied previously, our main goal now is to search for: i) the density contrasts between jets

We report TIMMI2 diffraction-limited mid-IR images of the multipolar PPN IRAS 16594-4656. By using the Lucy-Richardson deconvolution algorithm we recover a two-peaked morphology in the innermost region at 8.6 μm and 11.5 μm. We interpret the observed mid-IR structure as the detection of the two limb-brightened peaks indicating the presence of a

We present a new estimate of the mass of the Milky Way, making use of a large sample of 955 field horizontal-branch (FHB) stars from the Early Data Release of the Sloan Digital Sky Survey. This sample of stars has been classified on the basis of an automated analysis approach, in combination with other methods, in order to obtain estimates of the