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The Radial Velocity Experiment (rave): Second Data Release
We present the second data release of the Radial Velocity Experiment(RAVE), an ambitious spectroscopic survey to measure radial velocitiesand stellar atmosphere parameters (temperature, metallicity, surfacegravity, and rotational velocity) of up to one million stars using the 6dF multi-object spectrograph on the 1.2 m UK Schmidt Telescope of theAnglo-Australian Observatory (AAO). The RAVE program started in 2003,obtaining medium resolution spectra (median R = 7500) in the Ca-tripletregion (8410-8795 Å) for southern hemisphere stars drawn from theTycho-2 and SuperCOSMOS catalogues, in the magnitude range 9 < I <12. Following the first data release, the current release doubles thesample of published radial velocities, now containing 51,829 radialvelocities for 49,327 individual stars observed on 141 nights between2003 April 11 and 2005 March 31. Comparison with external data setsshows that the new data collected since 2004 April 3 show a standarddeviation of 1.3 km s–1, about twice as good as for thefirst data release. For the first time, this data release containsvalues of stellar parameters from 22,407 spectra of 21,121 individualstars. They were derived by a penalized χ2 method usingan extensive grid of synthetic spectra calculated from the latestversion of Kurucz stellar atmosphere models. From comparison withexternal data sets, our conservative estimates of errors of the stellarparameters for a spectrum with an average signal-to-noise ratio (S/N) of~40 are 400 K in temperature, 0.5 dex in gravity, and 0.2 dex inmetallicity. We note however that, for all three stellar parameters, theinternal errors estimated from repeat RAVE observations of 855 stars areat least a factor 2 smaller. We demonstrate that the results show nosystematic offsets if compared to values derived from photometry orcomplementary spectroscopic analyses. The data release includes propermotions from Starnet2, Tycho-2, and UCAC2 catalogs and photometricmeasurements from Tycho-2 USNO-B, DENIS, and 2MASS. The data release canbe accessed via the RAVE Web site: http://www.rave-survey.org andthrough CDS.
| CCD astrometry and UBV photometry of visual binaries. II. Visual double stars with mainly G - type primaries and relatively small angular separation
Differences Delta V of magnitude and Delta (B-V) and Delta (U-B)colours, as well as separations and position angles of 42 relativelyclose double stars are presented. The selection criteria of our sampleare: the relatively small separation (between 2.5 and 5 arcseconds),magnitude difference under 1.25 mag, and mainly G-type primaries. TheCCD observations, performed at the 90 cm Dutch telescope at ESO, weremade using the Bessel U, B and V filters; the astrometry was done in theV filter only. From the analysis of the photometric data we concludethat 16 binaries in our sample have components with practically the sameT_eff, since they have almost the same colours; one binary hascomponents with identical characteristics. We also note the goodinternal accuracy of the astrometric CCD measurements. Based onobservations made at ESO La Silla, Chile.
| The South Galactic Pole - Results from uvby-beta photometry of 572 O-F stars
Photometric observations on the uvby-beta system are presented for 572O-F stars within about 20 deg of the South Galactic Pole. Theinterstellar extinction near the pole is found to be zero out to 400 pcfrom the sun, in agreement with the H I maps of Burstein and Heiles(1982). Several evolved and Population II objects are identified.
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| Takýmyýldýz: | Balina |
| Sað Açýklýk: | 01h35m27.50s |
| Yükselim: | -16°47'34.6" |
| Görünürdeki Parlaklýk: | 9.683 |
| özdevim Sað Açýklýk: | -10.2 |
| özdevim Yükselim: | -6.4 |
| B-T magnitude: | 10.375 |
| V-T magnitude: | 9.741 |
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