Based on optical and near-infrared ground-based spectroscopy and optical and near-infrared Hubble Space Telescope (HST) images, we confirm the classification of Hen 401 as a bipolar proto-planetary nebula. HST images reveal a highly elongated morphology, consisting of two main bipolar lobes of unequal surface brightness separated by a dark lane of

We present an RI photometric survey covering an area of 430 arcmin2 around the multiple star sigma Orionis. The observations were conducted with the 0.8 m IAC-80 Telescope at the Teide Observatory. The survey limiting R and I magnitudes are 22.5 and 21, and completeness magnitudes 21 and 20, respectively. We have selected 53 candidates from the I

A sample of 47 faint Gigahertz Peaked Spectrum (GPS) radio sources selected from the Westerbork Northern Sky Survey (WENSS) has been imaged in the optical and near-infrared, resulting in an identification fraction of 87 per cent. The R-IR-K colours of the faint optical counterparts are as expected for passively evolving elliptical galaxies

Aims. Recent studies have detected linear polarization in L dwarfs in the optical I band. Theoretical models have been developed to explain this polarization. These models predict higher polarization at shorter wavelengths. We discuss the polarization in the R and I band of 4 ultra cool dwarfs. Methods: We report linear polarization measurements of

We analyzed first optical observations of 17 kyr-old PSR J2021+3651 and its pulsar wind nebula obtained with the 10.4-m Gran Telescopio Canarias (GTC) telescope in the Sloan r' band. In addition, we reanalyzed archival X-ray data obtained with Chandra. The pulsar and the nebula were not detected in the optical down to 27.20 and 24.85 magnitude 3σ

We report recent observational results of some ULXs collected with the 8.2m Subaru and with the ESO VLT telescopes. These observations have provided important information on the (inter-) stellar environments and have allowed to detect the optical counterparts of several ULXs. In two cases spectroscopic observations show stellar HeIIλ4686 optical