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מאמרים קשורים
Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
| 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.
| Two-dimensional spectroscopy of the Seyfert galaxies NGC 5728 and 4151 in the [OIII] lambdalambda4959, 5007 and H? spectral ranges
We have performed two-dimensional spectroscopy of the Seyfert galaxiesNGC 5728 and 4151 in the 4500-7500A spectral range. The data (especiallythe [OIII] lambdalambda4959, 5007 lines), obtained using a new opticalfibre system, complement previous observational work carried out bymeans of this technique. The two gaseous components found in NGC 5728seem to be ionized by the same source, although they have differentkinematics. They coexist (projected) in a strip-shaped zone aligned inthe NE-SW direction. We propose that one of the components, probablyrelated to outflow, energies at the north-west edge of the obscuringmaterial which hides the nucleus and gives rise to the biconicalstructure of ionization observed in NGC 5728. The cones of ionizingradiation seem to be tilted with respect to the galaxy's plane. Thevelocity field of NGC 4151 derived from the ionized gas is complex,showing two receding poles. Hence the location of the kinematical centreis not straight-forward and the active nucleus could be off-centre. Themaxima of the line-intensity and several continuum maps are inpositional agreement within an uncertainty of +/-0.13 arcsec, however,in contrast with previous results. In addition, from the ellipticalfitting of the surface brightness distribution in the I band, it may beinferred that the optical nucleus lies at the centre of a remarkablyregular and spherical galactic bulge. This seems to establish theidentification of the optical nucleus with the galaxy's mass centroid.One result common to these galaxies is that similar kinematicalproperties are inferred from the [OIII] and H? narrow emissionlines. This contrasts with the differences found in other Seyfertgalaxies like NGC 7469 or 3227 where two ionization sources(starburst-like and AGN-like) associated with different kinematicalsystems seem to coexist.
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משמש של הקבוצה הבאה
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | משולש |
| התרוממות ימנית: | 02h29m13.80s |
| סירוב: | +29°04'03.3" |
| גודל גלוי: | 9.224 |
| תנועה נכונה: | 0.5 |
| תנועה נכונה: | -3.6 |
| B-T magnitude: | 10.996 |
| V-T magnitude: | 9.371 |
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