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New periodic variables from the Hipparcos epoch photometry
Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
| GPM - compiled catalogue of absolute proper motions of stars in selected areas of sky with galaxies.
Not Available
| GPM1 - a catalog of absolute proper motions of stars with respect to galaxies
The description of the first version of the General Compiled Catalogueof Absolute Proper Motions (GPM1) for a sample of HIPPARCOS stars,derived with respect to galaxies within the plan called Catalogue ofFaint Stars (KSZ, Deutch 1952), is presented. The principal aim of theGPM1 construction was to provide absolute proper motions of stars todetermine the rotation of the HIPPARCOS system. The GPM1 cataloguecontains 977 HIPPARCOS Input Catalogue stars with V magnitudes $5^m -11^m in 180 fields north of -25 degrees of declination. The accuracy ofthe proper motions is 8 mas/yr (milliarcseconds per year). Comparison ofproper motions of GPM1 with those of the PPM and ACRS was performed andanalyzed with respect to systematic errors caused by spurious rotationof the FK5 system. The standard errors show that the rotation may bedetermined with an accuracy better than 1 mas/yr. Catalog is onlyavailable in electronic form at the CDS via anonymous ftpcdsarc.u-strasbg.fr or ftp 130.79.128.5.
| Photometric survey near the main Galactic meridian: 2.1. Finding charts and photoelectric U,B,V,R stellar magnitudes in 25 fields
Finding charts and photoelectric U,B,V,R magnitudes of stars in 25fields in the Main Galactic Meridian (programme MEGA) are presented.This part of the photometric survey includes fields near the NorthGalactic pole and fields at southern Galactic latitudes. Together withthe finding charts of 2.5(deg) x2.5(deg) the equatorial coordinates ofthe stars are given for epoch and equinox 1950.
| Photometric Survey Near the Main Galactic Meridian - Part One - Photoelectric Stellar Magnitudes and Colours in the UBVR System
Not Available
| An infrared-optical study of IRAS point sources in the Virgo region
Optical identifications for 199 of the 206 IRAS point sources in a 113sq deg area centered on the Virgo cluster are made using four deepIIIa-J plates obtained with the 1.2-m UK Schmidt Telescope. Only 4percent of the E and S0 galaxies brigher than B = 16 are detected, ascompared with 44 percent of the Sc galaxies. Infrared properties of theVirgo cluster are found to be similar to those of field galaxies atsimilar redshifts. Such IRAS galaxies are typical spirals with B of lessthan about 14, infrared to optical luminosity ratios of about 1, andinfrared luminosities of about 10 to the 9th solar luminosities,properties which are independent of neutral hydrogen content for theVirgo cluster galaxies. Data suggest that the optically faint galaxieshave L(IR) of greater than 10 to the 12th solar luminosities.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Bereniké Haja |
| Rektaszcenzió: | 12h29m05.68s |
| Deklináció: | +13°57'01.2" |
| Vizuális fényesség: | 8.773 |
| Távolság: | 10000000 parszek |
| RA sajátmozgás: | -5.8 |
| Dec sajátmozgás: | 5.1 |
| B-T magnitude: | 10.935 |
| V-T magnitude: | 8.952 |
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INHABITED SKY
