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Mass-radius relation of low and very low-mass stars revisited with the VLTI
We measured the radii of 7 low and very low-mass stars using longbaseline interferometry with the VLTI interferometer and its VINCI andAMBER near-infrared recombiners. We use these new data, together withliterature measurements, to examine the luminosity-radius andmass-radius relations for K and M dwarfs. The precision of the newinterferometric radii now competes with what can be obtained fordouble-lined eclipsing binaries. Interferometry provides access to muchless active stars, as well as to stars with much better measureddistances and luminosities, and therefore complements the informationobtained from eclipsing systems. The radii of magnetically quiet late-Kto M dwarfs match the predictions of stellar evolution models very well,providing direct confirmation that magnetic activity explains thediscrepancy that was recently found for magnetically active eclipsingsystems. The radii of the early K dwarfs are reproduced well for amixing length parameter that approaches the solar value, asqualitatively expected.Based on data collected with the VLTI/VINCI and VLTI/AMBER instrumentsat ESO Paranal Observatory, programmes ID 60.A-9220, 080.D-0653 and082.D-0196.
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry
We present in this paper a catalog of reference stars suitable forcalibrating infrared interferometric observations. In the K band,visibilities can be calibrated with a precision of 1% on baselines up to200 meters for the whole sky, and up to 300 meters for some part of thesky. This work, extending to longer baselines a previous catalogcompiled by Bordé et al. (2002, A&A, 393, 183), isparticularl y well adapted to hectometric-class interferometers such asthe Very Large Telescope Interferometer (VLTI, Glindemann et al. 2003,Proc. SPIE, 4838, 89) or the CHARA array (ten Brummelaar et al. 2003,Proc. SPIE, 4838, 69) when one is observing well-resolved, high-surfacebrightness objects (K 8). We use the absolute spectro-photometriccalibration method introduced by Cohen et al. (1999, AJ, 117, 1864) toderive the angular diameters of our new set of 948 G8-M0 calibratorstars extracted from the IRAS, 2MASS and MSX catalogs. Angular stellardiameters range from 0.6 mas to 1.8 mas (median is 1.1 mas) with amedian precision of 1.35%. For both the northern and southernhemispheres, the closest calibrator star is always less than 10°away.
| CHARM2: An updated Catalog of High Angular Resolution Measurements
We present an update of the Catalog of High Angular ResolutionMeasurements (CHARM, Richichi & Percheron \cite{CHARM}, A&A,386, 492), which includes results available until July 2004. CHARM2 is acompilation of direct measurements by high angular resolution methods,as well as indirect estimates of stellar diameters. Its main goal is toprovide a reference list of sources which can be used for calibrationand verification observations with long-baseline optical and near-IRinterferometers. Single and binary stars are included, as are complexobjects from circumstellar shells to extragalactic sources. The presentupdate provides an increase of almost a factor of two over the previousedition. Additionally, it includes several corrections and improvements,as well as a cross-check with the valuable public release observationsof the ESO Very Large Telescope Interferometer (VLTI). A total of 8231entries for 3238 unique sources are now present in CHARM2. Thisrepresents an increase of a factor of 3.4 and 2.0, respectively, overthe contents of the previous version of CHARM.The catalog is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/431/773
| The Southern Vilnius Photometric System. IV - The E region standard stars
This paper is the fourth in a series on the extension of the Vilniusphotometric system to the Southern Hemisphere. Observations were made of60 stars in the Harvard Standard E regions to increase a set of standardstars.
| Secondary standards for H-beta photometry in the Southern Hemisphere (second series).
Not Available
| UBV (RI)c standard stars in the E- and F-regions and in the Magellanic Clouds - a revised catalogue.
Not Available
| UBV photometry of E region standard stars of intermediate brightness
Photometry data are given for 335 stars in the nine E regions.Observations were made using a photometer and filters on the 47 cmreflector at Cape Town. The stellar dispersions are summarized. Data arepresented in tabular form.
| Photometric standard stars for the UBV and (RI)KC systems.
Not Available
| Fainter Standards for VRI Photometry in the E Regions
Not Available
| UBV photometry for star clusters in the Small Magellanic Cloud.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...34..431A&db_key=AST
| Standard magnitudes in the E regions.
Not Available
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Osservazione e dati astrometrici
| Costellazione: | Gru |
| Ascensione retta: | 22h47m09.11s |
| Declinazione: | -41°41'30.7" |
| Magnitudine apparente: | 6.838 |
| Distanza: | 232.019 parsec |
| Moto proprio RA: | 24.3 |
| Moto proprio Dec: | 6 |
| B-T magnitude: | 8.499 |
| V-T magnitude: | 6.976 |
Cataloghi e designazioni:
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