We propose to continue a northern sky program using high resolution, moderate S/N spectra to discover the chemically oldest stars - ultra metal-poor dwarfs and giants drawn from the Hamburg/ESO and SEGUE surveys. With these data we seek to (1) discover more stars with [Fe/H] -4.0 (only three of which are known and all of which our group has

We present results from a photometric Hα survey of 22 nuclear rings, aiming to provide insight into their star formation properties, including age distribution, dynamical timescales, star formation rates, and galactic bar influence. We find a clear relationship between the position angles and ellipticities of the rings and those of their host

We report optical spectroscopy of LSPM J1528+5937, the proposed optical counterpart to the recently discovered X-ray transient XMMSL1 J152835.4+593754 (Saxton et al. 2008, ATel #1361). A 900s spectrum was acquired starting on 2008 Jan 20 05:43 UT using the 4.2m William Herschel Telescope on La Palma equipped with the dual-beam ISIS spectrograph

The use of classical techniques for neutron flux measurements in nuclear reactors involves the switching between several detection chains as the power grows up to 10 decades. In space applications where mass and size constraints are of key significance, such volume of hardware represents a clear disadvantage. Instead of requiring different

Context: PG 1159-035, a pre-white dwarf with Teff≃ 140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained with the Whole Earth Telescope (WET) showed a rich frequency spectrum allowing the identification of 122 pulsation modes. Analyzing

We present a study of 66 barred, early-type (S0-Sb) disk galaxies, focused on the disk surface brightness profile outside the bar region, with the aim of throwing light on the nature of Freeman type I and II profiles, their origins, and their possible relation to disk truncations. This paper discusses the data and their reduction, outlines our