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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
| CHARM: A Catalog of High Angular Resolution Measurements
The Catalog of High Angular Resolution Measurements (CHARM) includesmost of the measurements obtained by the techniques of lunaroccultations and long-baseline interferometry at visual and infraredwavelengths, which have appeared in the literature or have otherwisebeen made public until mid-2001. A total of 2432 measurements of 1625sources are included, along with extensive auxiliary information. Inparticular, visual and infrared photometry is included for almost allthe sources. This has been partly extracted from currently availablecatalogs, and partly obtained specifically for CHARM. The main aim is toprovide a compilation of sources which could be used as calibrators orfor science verification purposes by the new generation of largeground-based facilities such as the ESO Very Large Interferometer andthe Keck Interferometer. The Catalog is available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/386/492, and from theauthors on CD-Rom.
| New binary stars discovered by lunar occultations. V
We present recent results from our ongoing lunar occultation program onbinary stars at the TIRGO and Calar Alto observatories. Observations arepresented here for a total of seventeen sources, the majority of whichare resolved for the first time. These include SAO94621, IRAS 18154-1900, SAO98345, SAO 98363, SAO93947, SAO 97319, SAO97437, SAO 94986, SAO94488, DO 11742, SAO78027 and SAO 79799. Two speckle binarieswere also observed, namely SAO 98427 and SAO110723; this latter is discovered to be a quadruple system.SAO 77810 is found to be a new triple system. In thecases of SAO 94621 and SAO 98363,we have recorded two occultation light curves each, at differentposition angles: this allowed us to derive actual position angles andseparations for these binary systems. We report an observation of theoccultation binary SAO 94961, for which we could notdetect the companion. Finally, we report also an observation of thewell-studied multiple system SAO 97645 (zetaCnc), which is discussed in detail in a separate paper. Basedon observations collected at TIRGO (Gornergrat, Switzerland), and atCalar Alto (Spain). TIRGO is operated by CNR-CAISMI Arcetri, Italy.Calar Alto is operated by the German-Spanish Astronomical Center.
| Radio continuum emission from stars: a catalogue update.
An updated version of my catalogue of radio stars is presented. Somestatistics and availability are discussed.
| A 1.5 GHz radio survey of the Hyades open stellar cluster
Results of a radio survey of the Hyades open stellar cluster carried outwith the VLA at 1.5 GHz are reported. Seventeen fields containing over150 cataloged stars were mapped down to a limiting sensitivity rangingfrom 0.3 mJy at the centers of the fields to 0.9 mJy at a distance of 20arcmin from field centers. Two stars were detected as radio sources: theevolved spectroscopic binary V471 Tau, consisting of a white dwarf and ared dwarf; and the apparently premain-sequence G+K star spectroscopicbinary HD 27130. The failure to detect any single stars as radio sourcesis generally consistent with the age-rotation-activity paradigm,according to which stellar activity is due to magnetic fields producedby dynamo action in rapidly rotating stars and should decrease with ageas a star spins down due to magnetic braking. It is concluded that theHyades M dwarf population is not more active at radio wavelengths thanthe nearby flare star population, or else the number of flare stars inthe Hyades is much less than presently assumed.
| Photometry of astrometric reference stars
UBVRI, DDO, and uvby, H-beta photometry of astrometric reference starsis presented. Spectral types and luminosity classifications made fromthe colors are used to determine their spectroscopic parallaxes. In thispaper, colors for 309 stars in 25 regions are given, and classificationsfor 210 stars have been made. These stars form reference frames in theAllegheny Observatory Multichannel Astrometric Photometer astrometricprogram, and in the Praesepe cluster reduced by Russell (1976). It isfound that the present photometric spectral types are reliable to within2.5 spectral subclasses.
| Helligkeiten und Eigenbewegungen in den Hyaden. Mit 6 Textabbildungen
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Pozíciós és asztrometriai adatok
| Csillagkép: | Bika |
| Rektaszcenzió: | 04h28m20.32s |
| Deklináció: | +16°18'04.0" |
| Vizuális fényesség: | 8.214 |
| RA sajátmozgás: | 5.9 |
| Dec sajátmozgás: | -10.5 |
| B-T magnitude: | 10.13 |
| V-T magnitude: | 8.373 |
Katalógusok és elnevezések:
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