We solve the line transfer problem in evolving H ii regions in order to calculate line profiles of hydrogen recombination (Hα) and forbidden oxygen ([O III] 5007) lines along several lines of sight during the photo- disruption of molecular cloud cores, or high-density condensation. The density, velocity, and ionization structure of spherically

Utilizing the unique location of red clump giants on colour-magnitude diagrams obtained from various near-infrared surveys, we derived specific reddening-distance relations towards 119 Galactic novae for which independent reddening measurements are available. Using the derived distance-extinction relation and the independent measurements of

The double-mode pulsation of GSC 00144-03031 has been detected when searching for COROT targets. A very large dataset composed of 4722 photometric measurements was collected at six observatories in Europe and America. There is no hint of the excitation of additional modes (down to 0.6 mmag) and therefore GSC 00144-03031 seems to be a pure double

We present a model of the dust environment of Main-Belt Comet P/2010 R2 (La Sagra) from images acquired during the period 2010 October-2011 January. The tails are best simulated by anisotropic ejection models, with emission concentrated near the nucleus south pole, the spin axis having an obliquity near 90°, indicative of a possible seasonally

We study the dynamical status of the galaxy system ZwCl 2341.1+0000, a filamentary multi-Mpc galaxy structure associated with a complex diffuse radio emission. Our analysis is mainly based on new spectroscopic data for 128 galaxies acquired at the Italian Telescopio Nazionale Galileo. We also use optical data available in the Sloan Digital Sky

We apply the spherical infall model to compare the observed distribution of radial velocities of galaxies around Coma with predictions that are based on optical and X-ray overdensity profiles. Two optically selected galaxy catalogues, the CfA redshift survey and a UKST plate scanned with the APM, are used to determine the overdensity profile of the