Some of the world's largest telescopes and largest concentrations of telescopes are on sites in Arizona and the Canary Islands. Active site protection efforts are underway in both regions; the common challenge is getting out ahead of the LED revolution in outdoor lighting. We review the work with local, regional, and national government bodies

We report on our ongoing project "Statistical studies of HII regions in the nearby extra-galaxies". In this report we present the overview of our detailed study of warm dust in the nearby Galaxy NGC 4321 (M100). We measure the flux values in the 4 Spitzer-IRAC bands of some 275 HII regions in M100. In addition, we also present our new measurements

The Andromeda Galaxy recurrent nova M31N 2008-12a had been caught in eruption eight times. The inter-eruption period of M31N 2008-12a is ~1 yr, making it the most rapidly recurring system known, and a strong single-degenerate Type Ia supernova progenitor candidate. Following the 2013 eruption, a campaign was initiated to detect the predicted 2014

We report the discovery of a new totally eclipsing binary (R.A. = {06}{{h}}{40}{{m}}{29}{{s}}11; decl. = +38°56‧52″2 J = 2000.0; Rmax = 17.2 mag) with an sdO primary and a strongly irradiated red dwarf companion. It has an orbital period of Porb = 0.187284394(11) day and an optical eclipse depth in excess of 5 mag. We obtained 2 low-resolution

We have observed a sample of 12 interacting galaxies using the Fabry-Perot interferometer GHαFaS (Galaxy Hα Fabry-Perot system) on the 4.2m William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos, La Palma, deriving maps in Hα surface brightness, velocity and velocity dispersion. We extracted the physical parameters (Hα

During the late stages of their evolution, Sun-like stars bring the products of nuclear burning to the surface. Most of the carbon in the Universe is believed to originate from stars with masses up to a few solar masses. Although there is a chemical dichotomy between oxygen-rich and carbon-rich evolved stars, the dredge-up itself has never been