In an effort to test stellar structure and evolution models, analysis of oscillations in A and F stars in open clusters is carried out by the STACC network (Frandsen cite{stacc}). In this paper we describe our effort to locate a suitable open cluster in the northern hemisphere for a future multi-site campaign. We present BV Johnson and time series

One of the classical tests of the early dynamical evolution of the Milky Way is the prediction of the monolithic collapse model (e.g., Eggen, Lynden-Bell, & Sandage 1962) of a decline in the mean stellar abundance of the halo population as one proceeds to stars at greater distances, or equivalently, with higher local space velocities in the solar

Aims.We present a study of the neutron star X-Ray Transient Cen X-4. Our aim is to look for any evidence of irradiation of the companion with a detailed analysis of its radial velocity curve, relative contribution of the donor star and Doppler tomography of the main emission lines. Methods: .To improve our study all our data are compared with a set

Brown dwarfs with thick water cloud atmospheres, ancient population III brown dwarfs, and nearby free-floating planetary mass objects are targets in our new discovery space. We have developed a candidate selection process that identifies near infrared sources without optical counterparts whose infrared/optical fluxes are not consistent with stars

Very young late-type dwarfs at distances closer than 30 pc are excellent sites to provide a direct detection of extrasolar planets. The combination of youth and proximity makes feasible the detection of giant planets of 1-5 Jovian masses orbiting at several astronomical units from the star. According to current models, giant planets with masses 1

Recent star count surveys of areas around globular star clusters have shown strong evidence of tidal tails stretching out many degrees beyond the cluster tidal radius. These tails are believed to be cluster stars which have escaped due to tidal shocking after passages through the disk of the Galaxy. Although the statistical star counts indicate and