We present photometric and spectroscopic data of the Type II-P supernova (SN II-P) 2003gd, which was discovered in M74 close to the end of its plateau phase. SN 2003gd is the first Type II supernova (SN) to have a directly confirmed red supergiant (RSG) progenitor. We compare SN 2003gd to SN 1999em, a similar SN II-P, and estimate an explosion date

We exploit deep combined observations with Spitzer and Chandra of the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE) in the ELAIS N1 region to investigate the nature of the faint X-ray and IR sources in common, to identify active galactic nucleus (AGN)/starburst diagnostics, and to study the sources of the X-ray and IR cosmic backgrounds

In order to characterize the low surface brightness component in blue compact dwarf galaxies, we determine their structural parameters for eight objects by fitting a Sérsic law to their B, V, and R light profiles. We restrict the fit to the outer regions, excluding the starburst emission with the help of color and Hα maps. We discuss the problems

The vertical distribution of K giants stars is analyzed using 2MASS data and a semiempirical method of extracting stellar densities from the K/J-K colour-magnitude diagrams. The vertical density distribution of red clump giant stars can be described by a double exponential, with scaleheights of 268.81 ± 12.65 pc and 1061.9 ± 52.16 pc. These values

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We present spectroscopic observations of six optical counterparts of ultraluminous X-ray sources (ULXs) around nearby galaxies. The spectra of the six objects show the presence of broad emission features. The identification of these allow us to classify all of the objects as quasars at higher redshift than their assigned parent galaxy. This is one