We report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. At a distance of 12.50+0.75-0.67 pc, the angular separation of 32 arcsec corresponds to a projected separation of 400 au. The M4 primary displays no Hα emission, and we apply the age-activity relations of West et al. to place a lower limit on the age of the

The near-UV NH3360 feature has been measured in a sample of 35 early-type galaxies spanning a wide range of masses and environments. We found that, contrary to what is seen with Mg- and C-sensitive Lick-style indices, NH3360 does not vary significantly with galaxy velocity dispersion. When compared with solar-scaled stellar population models N/Fe

We propose a new chemical evolution model aimed at explaining the chemical properties of globular clusters (GCs) stars. Our model depends upon the existence of (i) a peculiar pre-enrichment phase in the GC's parent galaxy associated with very low-metallicity Type II supernovae (SNe II) and (ii) localized inhomogeneous enrichment from a single Type

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We describe the highly variable X-ray and UV emission of V458 Vul (Nova Vul 2007), observed by Swift between 1 and 422 days after outburst. Initially bright only in the UV, V458 Vul became a variable hard X-ray source due to optically thin thermal emission at kT = 0.64 keV with an X-ray band unabsorbed luminosity of 2.3 × 1034 erg s-1 during days

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