Complete uvby light curves of the detached triple-lined late B-type eclipsing binary V906 Scorpii, obtained from 1987 to 1991, are presented. A detailed photometric analysis based on these observations and on new spectroscopic material yields accurate masses and radii (errors <2%) for the components, confirms that the system is member of NGC 6475 (Messier 7) and is published separately (Alencar et al., 1997A&A...326..709A)
Trans-Neptunian objects (TNOs) represent a new frontier in the study of our Solar System. In particular, the investigation of their rotational properties can provide important hints about their internal structure and collisional evolution. We expand the limited sample of TNOs with known rotation rates, and improve the knowledge of the physical nature of these bodies.
Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the electron multiplying CCD (EMCCD) camera at the Danish 1.54m Telescope at La Silla, Chile. The two variables were not previously detected by conventional CCD imaging because of their proximity to a bright star. This discovery demonstrates that EMCCDs are a powerful tool for performing high-precision time-series photometry in crowded fields and near bright stars, especially when combined with difference image analysis.
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains the largest number of homogeneously observed and reduced nearby SNe Ia (z<~0.08) published to date. It more than doubles the nearby sample, bringing SN Ia cosmology to the point where systematic uncertainties dominate. Our natural system photometry has a precision of <~0.02mag in BVRIr'i' and <~0.04 mag in U for points brighter than 17.5mag. We also estimate a systematic uncertainty of 0.03mag in our SN Ia standard system BVRIr'i' photometry and 0.07mag for U. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars, where available for the same SN, reveal agreement at the level of a few hundredths mag in most cases. We find that 1991bg-like SNe Ia are sufficiently distinct from other SNe Ia in their color and light-curve-shape/luminosity relation that they should be treated separately in light-curve/distance fitter training samples.
We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15<z<1.1) discovered during the first three years of the Supernova Legacy Survey (SNLS). These events were detected and their multi-colour light curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshifts.
We present optical (uBgVri) and near-infrared (YJHKs) photometry of Type IIn Supernovae 2005kj, 2006aa, 2006bo, 2006qq, 2008fq, obtained by the Carnege Supernova Project. We also report the magnitudes of the local sequence stars for each of the five supernovae.
Periods and light curves of 12 variable stars of the globular cluster NGC 6229 have been determined. The photographic magnitudes are given for 4 other variables. Observations were obtained at the Asiago observatory, in the years 1956-57-58.
We present a variable star catalog of an extensive ground-based wide-field variability survey in the globular cluster omega Centauri. Using the Australian National University 40 inch (1m) telescope at Siding Spring Observatory, the cluster was observed with a 52'x52' (0.75deg^2^) field for 25 nights, from 2003 May 2 to May 27. A total of 187 variable stars were identified in the field, 81 of which are new discoveries. This work comprises the widest field variability survey yet undertaken for this cluster. Here we present the V+R light curves and preliminary analysis of the detected variable stars, comprising 58 eclipsing binaries, 69 RR Lyrae stars, 36 long-period variables (P>=2days), and 24 miscellaneous pulsators including 15 SX Phoenicis stars and two type II Cepheids.
We analyze spectra of V838 Mon and V4332 Sgr taken in 2004-2005 using the 6m telescope of the Special Astrophysical Observatory with the UAGS and SCORPIO spectrographs. We conclude based on spectroscopy combined with archive photographs and modern CCD photometry that both peculiar red novae were binaries prior to their outbursts, and contained blue hot components that exploded. The secondary of V838 Mon is a hot B3V star, and that of V4332 Sgr is a cool M7 star.
We present broad-band photometry of 11 planetary transits of the hot Jupiter WASP-74 b, using three medium-class telescopes and employing the telescope-defocusing technique. Most of the transits were monitored through I filters and one was simultaneously observed in five optical (U, g', r', i', z') and three near-infrared (J, H, K) passbands, for a total of 18 light curves. We also obtained new high-resolution spectra of the host star. We used these new data to review the orbital and physical properties of the WASP-74 planetary system. We were able to better constrain the main system characteristics, measuring smaller radius and mass for both the hot Jupiter and its host star than previously reported in the literature. Joining our optical data with those taken with the HST in the near infrared, we built up an observational transmission spectrum of the planet, which suggests the presence of strong optical absorbers, as TiO and VO gases, in its atmosphere.