We report the results of CCD V and R photometry of the RR Lyrae stars in M2. The periodicities of most variables are revised and new ephemerides are calculated. Light-curve decomposition of the RR Lyrae stars was carried out and the corresponding mean physical parameters [Fe/H] = -1.47, Teff = 6276K, logL = 1.63Lsolar and MV = 0.71 from nine RRab

Aims.We study the optical spectral properties of a sample of stars showing far infrared colours similar to those of well-known planetary nebulae. The large majority of them were unidentified sources or poorly known in the literature at the time when this spectroscopic survey started, some 15 years ago. Methods: .We present low-resolution optical

We present a new 40ks XMM observation of the black hole X-ray nova V404 Cyg in quiescence. Its quiescent spectra can be best fitted by a power-law with slope Gamma 2 as found previously. V404 Cyg was roughly equal in luminosity compared to the previous observation of Chandra with variability of a factor of 4 during the observation. We find no

Data on linear optical polarimetry were obtained during two observing runs at the Complejo Astronomico El Leoncito (CASLEO) in San Juan, Argentina, in 2003 (April 29 to May 5 and August 29 to September 2). (1 data file).

We have studied the optical spectra of a sample of 31 O-and early B-type stars in the Small Magellanic Cloud, 21 of which are associated with the young massive cluster NGC 346. Stellar parameters are determined using an automated fitting method (Mokiem et al. 2005, A&A, 441, 711), which combines the stellar atmosphere code FASTWIND (Puls et al