We have carried out high angular resolution near-infrared imaging and low-resolution (R˜1000) spectroscopy of the nearest known brown dwarf, varepsilon Indi B, using the ESO VLT NAOS/CONICA adaptive optics system. We find it to be a close binary (as also noted by Volk et al. 2003), with an angular separation of 0.732 arcsec, corresponding to 2.65

An XMM-Newton target of opportunity observation of the field around the transient pulsar XTE J0055-727 (ATEL #214) in the Small Magellanic Cloud was performed on 2003-12-18 between 14:32 UT and 19:48 UT. Two bright X-ray sources were detected by the EPIC instruments. XMMU J005455.4-724512 is consistent in position with CXOU J005455.6-724510 = RX

The main aim of this paper is to report two new detections of tidal debris in the northern stream of the Sagittarius dwarf galaxy located at 45° and 55° from the center of the galaxy. Our observational approach is based on deep color-magnitude diagrams that provide accurate distances, surface brightness, and the properties of stellar population of

The variation of the mass-to-light M/L ratios of early-type galaxies as a function of their luminosities L is investigated. It is shown that the tilt β=0.27 (in the B band) of the fundamental plane relation M/L~Lβ can be understood as a combination of two effects: about one-quarter (i.e., Δβ=0.07) is a result of systematic variations of the stellar

In this paper we discuss the reason why the parameters of the Sérsic model best-fitting the major axis light profile of elliptical galaxies can differ significantly from those derived for the minor axis profile. We show that this discrepancy is a natural consequence of the fact that the isophote eccentricity varies with the radius of the isophote

We revise the explanation for the ``expanding H II regions ring'' of NGC 4736. From the analysis of long-slit spectra, we identify structures within the emission region previously reported in the literature as a single ring (former parameters: R~47", FWHM=21"). The H II ring is located at 35" (1.12 kpc) galactocentric distance, and its thickness is