We present a new determination of the interstellar 12CH+/13CH+ ratio in the solar neighbourhood, based on high spectral resolution CCD observations of the CH+ molecule in the direction of the star HD 26676 (d ≃ 150 pc). The measured absorption at λ4233 Å is one of the most intense 12CH+ lines detected so far (Wλ =23.5 mÅ), and is produced in the

We present the results of the study of visible (BVRI) intra-night variability of the BL Lac object OJ287. The observations were carried out on a total of 29 nights during the period November 1993-October 1994, with only nights with at least 4 observations being included. Three telescopes were used for the study: the 1m Jacobus Kapteyn Telescope and

We present a census of variable stars in six M31 dwarf spheroidal satellites observed with the Hubble Space Telescope. We detect 870 RR Lyrae (RRL) stars in the fields of And I (296), II (251), III (111), XV (117), XVI (8), and XXVIII (87). We also detect a total of 15 Anomalous Cepheids, three eclipsing binaries, and seven field RRL stars

GM 24 is a compact nebulous object immersed in the low-brightness HII region RCW 126. It is associated with a warm and dense CO cloud at whose centre a deeply embedded (A_V = 55) massive cluster of more than one hundred members is located. The most luminous young stellar object of the cluster, Irs 3 (= IRAS 17136-3617), radiates most of its energy

We present the rationale, first observations and preliminary results of our radial velocity search for exoplanets around M dwarfs. So far we have obtained 2.5 nights (1.5 already done, 2 half nights pending) of Keck NASA time to collect high-resolution near-infrared spectra using NIRSPEC on the KECK II telescope. Our sample consists of 80 nearby

Recent results from the Sloan Digital Sky Survey (SDSS) and the 2MASS All-Sky Survey have clearly revealed the extent of the spatial distribution of stars affiliated with the tidal debris tail of the Sagittarius Dwarf Galaxy (Sgr). Although these surveys help to constrain the shape of the Sgr orbit, kinematics of the tidal tail stars are crucial in