Related papers: Resolving the 47 Tucanae Distance Problem

Using deep Hubble Space Telescope imaging, color-magnitude diagrams are constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because of its lower metal abundance, the main sequence of NGC 6397 lies well to the blue of…

We report the first search for new star clusters performed using the VISTA near-infrared YJKs Magellanic Clouds survey (VMC) data sets. We chose a pilot field of ~ 0.4 deg^2 located in the South-West of the Small Magelllanic Cloud (SMC)…

We present J, H, Ks photometry from the the Multi conjugate Adaptive optics Demonstrator (MAD), a visitor instrument at the VLT, of a resolved stellar population in a small crowded field in the bar of the Large Magellanic Cloud near the…

Characterizing the sub-mm Galactic emission has become increasingly critical especially in identifying and removing its polarized contribution from the one emitted by the Cosmic Microwave Background (CMB). In this work, we present a…

We have detected 300 X-ray sources within the half-mass radius (2.79') of the globular cluster 47 Tucanae in a deep (281 ks) Chandra exposure. We perform photometry and simple spectral fitting for our detected sources, and construct…

This research aims to secure precise distances for cluster delta Scutis in order to investigate their properties via a VI Wesenheit framework. Deep JHKs colour-colour and ZAMS relations derived from ~700 unreddened stars featuring 2MASS…

We present the results of CCD UBVRI observations of the open cluster NGC 6811 obtained on 18th July 2012 with the 1m telescope at the T\"UB\.ITAK National Observatory (TUG). Using these photometric results, we determine the structural and…

Candidate clusters of galaxies drawn from the sample identified from the moderately deep I-band data of the ESO Imaging Survey (EIS), have been used for follow-up optical/infrared imaging and spectroscopic observations. The observations…

In this paper JK_s data from the VISTA Magellanic Cloud (VMC) survey are used to investigate the tip of the red giant branch (TRGB) as a distance indicator. A linear fit to recent theoretical models is used which reads M_{K_s} = -4.196…

We present preliminary trigonometric parallaxes and proper motions for 22 L dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager. Relative to absolute parallax corrections are made by employing 2MASS and/or SDSS photometry for…

We present a detailed map of the reddening in a 1.9 x 1.5 degree section of the Large Magellanic Cloud, constructed from UBVI photometry of 2069 O and B main sequence stars. We use two reddening-free photometric parameters to determine the…

We report here initial but still strongly conclusive results on absolute ages of galactic globular clusters (GGCs). This study is based on high precision trigonometric parallaxes from the HIPPARCOS satellite coupled with accurate metal…

This paper is the second in a series where we report the results of the long-term timing of the millisecond pulsars (MSPs) in 47 Tucanae with the Parkes 64-m radio telescope. We obtain improved timing parameters that provide additional…

We present a Mass-Luminosity Relation (MLR) for red dwarfs spanning a range of masses from 0.62 Msun to the end of the stellar main sequence at 0.08 Msun. The relation is based on 47 stars for which dynamical masses have been determined,…

We use deep Gemini/GMOS-S $g,r$ photometry to study the three ultra-faint dwarf galaxy candidates DES1, Eridanus III (Eri III) and Tucana V (Tuc V). Their total luminosities, $M_V$(DES1) $ = -1.42\pm0.50$ and $M_V$(Eri III) $ =…

Age constraints are most often placed on globular clusters by comparing their CMDs with theoretical isochrones. The recent discoveries of detached, eclipsing binaries in such systems by the Cluster AgeS Experiment (CASE) provide new…

We analyze ROSAT HRI observations obtained from 1992 to 1996 of the globular cluster 47 Tuc. Identifications of two X-ray sources with HD 2072 and with a galaxy, respectively, are used to obtain accurate (<2'') positions of the X-ray…

Approximately 14% of known Galactic open clusters possess absolute errors 20% as evaluated from n>3 independent distance estimates, and the statistics for age estimates are markedly worse. That impedes such diverse efforts as calibrating…

We present the first set of definitive trigonometric parallaxes and proper motions from the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI). Full astrometric reductions for the program are discussed, including…

We present the commissioning results and first scientific observations from the newly installed TWIST observatory - a 50 cm telescope equipped with an sCMOS camera providing a $36.1\times24.1$ arcmin$^2$ field of view - housed in the former…