We present the surface photometry and stellar kinematics of NGC 2950, which is a nearby and undisturbed SB0 galaxy hosting two nested stellar bars. We use the Tremaine-Weinberg method to measure the pattern speed of the primary bar. This also permits us to establish directly and for the first time that the two nested bars are rotating with

All the projects of the Extremely Large Telescopes (ELTs) are based on segmented primary mirrors. This idea, solving the problem of producing single mirrors having diameter larger than 8m, introduces the needs for an accurate co-phasing of the various segments. The paper presents some laboratory measurements aimed to investigate the use of the

Not Available

Not Available

Non-axisymmetric features such as bars drive the dynamical and secular evolution of disk galaxies by exerting gravitational torques which redistribute mass and angular momentum. While most (> 70 %) spirals are barred in the local Universe, early studies of the Hubble Deep Field (HDF) suggest a remarkably low bar fraction ( 20 %) at intermediate

We have compiled and studied photometric and spectroscopic data published in the literature of several star-forming regions and young open clusters (Orion, Taurus, IC 348, Sco-Cen complex, Chamaeleon I, TW Hydrae association, σ Orionis cluster, IC 2391, α Persei cluster, and the Pleiades). Our goal was to seek the definition of a simple empirical