Aims: We present the main results of an imaging survey of possible young massive clusters (YMC) in M 31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope (HST), with the aim of estimating their age and their mass. We obtained shallow (to B ˜ 25) photometry of individual stars in 19 clusters (of the 20

Context. According to theory, high-energy emission from the coronae of cool stars can severely erode the atmospheres of orbiting planets. No observational tests of the long-term erosion effects have been made yet. Aims: We analyze the current distribution of planetary mass with X-ray irradiation of the atmospheres to make an observational

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We present early results of our Chandra study of transient X-ray binaries (XRB) in IC 10, the youngest and most active starburst galaxy in the local universe. X-ray binaries containing black-holes and neutron stars are the relics of the most massive, short-lived stars, and are highly visible tracers of star formation. Visible at intergalactic

We present CCD photometry in the Washington-system C and T1 passbands down to T1 ~ 22.5 mag in the fields of NGC 1697, SL 133, NGC 1997, SL 663, and OHSC 28, five mostly unstudied star clusters in the LMC. Cluster radii were estimated from star counts in appropriately sized boxes distributed throughout the entire observed fields. We perform a

The three open clusters Be 15, Be 80 and NGC 2192 have been observed using CCD UBV(RI)C photometry at the San Pedro Mártir Observatory, México within the framework of our open-cluster survey. The fundamental parameters of interstellar reddening, distance and age have been derived, and also the metallicity for NGC 2192 (solar metallicity has been