Aims: We have selected the Galactic H ii region M 43, a close-by apparently spherical nebula ionized by a single star (HD 37061, B0.5 V) to investigate several topics of recent interest in the field of H ii regions and massive stars. In a series of two papers, we perform a combined, comprehensive study of the nebula and its ionizing star by using

NASA's Wide-field Survey Explorer (WISE) mapped the sky in four bands at 3.4, 4.6, 12, and 22 μm during its mission. Published on 14 April 2011, the WISE Preliminary Release provides data of more than 150,000 asteroids that were processed with initial calibration and reduction algorithms. Our aim is to carry out an analysis of key physical

The present work is based on the multi-wavelength catalog of IRAC 3.6+4.5um selected galaxies in the EGS (RA=14h14m, DEC=+53°30') presented in Paper I (Barro et al. 2011, Cat. J/ApJS/193/13). We cross-correlated our IRAC-selected catalog with the X-ray (Chandra) and radio (VLA/20cm) catalogs of Laird et al. (2009, Cat. J/ApJS/180/102) and Ivison et

The MASTER auto-detection system at Tunka (Baykal Lake) detected a new transient source at the position (R.A., Dec) = 17h 29m 00.07s , +75d 18m 42s.5, (J2000) with a typical uncertainty of 0.5" at 2011-05-12 18:24:47.725 (UT). The OT is seen at 2 images. There is no minor planet and any object brighter 21 mag in DSS at this place. The unfiltered (0

We present the results of a comprehensive study of the gamma-ray burst 080928 and of its afterglow. GRB 080928 was a long burst detected by Swift/BAT and Fermi/GBM. It is one of the exceptional cases where optical emission had already been detected when the GRB itself was still radiating in the gamma-ray band. For nearly 100 s simultaneous optical

We have identified the optical counterpart of the ULX source P13 in the nearby spiral galaxy NGC 7793. The object is a V ˜ 20.5 mag star, ten times brighter than any other established counterpart of a ULX in nearby galaxies. Medium resolution optical spectroscopy carried out in 2008 and 2009 with the ESO-VLT reveals the presence of narrow high