We report the first results of a Hubble Space Telescope (HST) program which performed WFPC2 multi-color imaging of a sample of A- and B-type supergiant stars in M31 and M33. This sample has previously been studied by us spectroscopically with the High Resolution Echelle Spectrograph (HIRES) on the 10m Keck-I Telescope. In particular, fits to the P

We present WeCAPP, a long term monitoring project searching for microlensing events towards M 31. Since 1997 the bulge of M 31 was monitored in two different wavebands with the Wendelstein 0.8 m telescope. In 1999 we extended our observations to the Calar Alto 1.23 m telescope. Observing simultaneously at these two sites we obtained a time coverage

We explore the application of artificial neural networks (ANNs) for the estimation of atmospheric parameters (Teff, logg, and [Fe/H]) for Galactic F- and G-type stars. The ANNs are fed with medium-resolution (Δλ~1-2 Å) non-flux-calibrated spectroscopic observations. From a sample of 279 stars with previous high-resolution determinations of

The photometric and morphological properties, as well as the star formation history, of the Draco dwarf spheroidal galaxy are analyzed on the basis of wide-field CCD photometry of the resolved stars covering about 1 deg2. Draco is at a distance of d=80+/-7 kpc and has a metallicity, [Fe/H], of -1.8+/-0.2. No metallicity gradient is detected. The

We report the discovery of the first hyperluminous infrared galaxy (HyLIG) in the course of the European Large Area ISO Survey (ELAIS). This object has been detected by ISO at 6.7, 15 and 90μm, and is found to be a broad-line, radio-quiet quasar at a redshift [formmu4]z=1.099. From a detailed multicomponent model fit of the spectral energy

IAUC 7745 available at Central Bureau for Astronomical Telegrams.