We have used fibre spectroscopy to establish cluster membership and examine premain-sequence (PMS) lithium depletion for low-mass stars (spectral types F to M) in the sparse young (≃ 30Myr) cluster IC 4665. We present a filtered candidate list of 40 stars that should contain 75 per cent of single cluster members with 11.5 < V < 18 in the central square degree of the cluster. Whilst Fand G-type ...

The Century Survey Galactic Halo Project is a photometric and spectroscopic survey from which we select relatively blue stars (V −R < 0.30 mag) as probes of the Milky Way halo. The Survey strip spans the range of Galactic latitude 35 < b < 88, allowing us to study the nature of populations of stars and their systematic motions as a function of Galactic latitude. One of our primary goals is to u...

We attempt to document complete energetic transactions of stars in their life. We calculate photon and neutrino energies that are produced from stars in their each phase of evolution from 1 to 8M⊙, using the state-of-the-art stellar evolution code, tracing the evolution continuously from pre-main sequence gravitational contraction to white dwarfs. We also catalogue gravitational and thermal ene...

1607 OH/IR stars associated with IRAS sources are assembled and the IRAS LRS spectra of 980 OH/IR stars are examined in this paper. The nature of the circumstellar dust for these sources is classiied. The distributions of these subgroups of OH/IR stars in the IRAS color{color diagram and the period{color diagram are interpreted with their evolutionary status. The Galactic and the velocity distr...

Most stars in our Galaxy with photospheric C/O > 1 (carbon stars) are not giants but dwarfs. The newly-recognized class of dwarf carbon stars joins the growing family of stars with peculiar abundances that are now recognized as products of mass-transfer binary (MTB) evolution. The dozen examples now known span a wide range of evolutionary histories, ages, and abundances. These stars can already...

We have obtained and analyzed UBVRI CCD frames of the young, 4–10Myr, open cluster NGC 3293 and the surrounding field in order to study its stellar content and determine the cluster’s IMF. We found significantly fewer lower mass stars, M ≤ 2.5M⊙, than expected. This is particularly so if a single age for the cluster of 4.6Myr is adopted as derived from fitting evolutionary models to the upper m...

We report observations of a deep near-ultraviolet (NUV) survey of the Kepler field made in 2012 with the Galaxy Evolution Explorer (GALEX) Complete All-Sky UV Survey Extension (CAUSE). The GALEX-CAUSE Kepler survey (GCK) covers 104 square degrees of the Kepler field and reaches limiting magnitude NUV ≃ 22.6 at 3σ. Analysis of the GCK survey has yielded a catalog of 669,928 NUV sources, of which...

We propose a new approach to unveil the presence of binary intermediate mass black holes (IMBHs) in the core of globular clusters (GCs). We study the signature that a binary IMBH imprints on the velocity and on the angular momentum of cluster stars, simulating 3-body encounters between a star and a binary IMBH. We find that the binary IMBH generates a family of few hundreds of stars (∼ 100-300)...

An ∼800 arcmin mosaic image of the W3 star forming complex obtained with the Chandra X-ray Observatory gives a valuable new view of the spatial structure of its young stellar populations. The Chandra image reveals ∼ 1300 faint X-ray sources, most of which are PMS stars in the cloud. Some, but not all, of the high-mass stars producing hypercompact and ultracompact HII (UCHII) regions are also se...

We compare (V − I)0–(V −K)0 color-color and (V − I)0–log P period–color diagrams for Baade’s Window and local RRab Lyrae stars. We find that for a fixed log P the Baade’s Window RR Lyrae stars are ∼ 0.17 magnitudes redder in (V − I)0 than the local RR Lyrae stars. We also show that there is no such effect observed in (V − K)0. We argue that an extinction misestimate towards Baade’s Window is no...