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1.
We describe the modifications made in the design of the Kyiv meridian axial circle (MAC) and in the observation technique after the instrument was equipped with a CCD camera with an array of 1040×1160 pixels. The observations are performed in the drift-scan mode (time-delay imaging) with an effective exposure time of 108 s for equatorial stars. The MAC photometric system reproduces the standard V system; the limiting magnitude is V = 17 m . The observations made with the modified MAC in 2001–2003 served as the basis for the KMAC1 catalog which contains positions, proper motions, and magnitudes B, V, R, r′, J for 100 000 stars in the sky areas with the ICRF objects. The errors of positions and V magnitudes in the catalog are 50–90 mas and 0.1 m , respectively, for stars with V = 15 m . Stars in the equatorial sky areas and radio stars are presently observed with the aim to determine their exact positions, proper motions, and magnitudes. The catalogs are available in the data base of the Centre de Données Astronomiques de Strasbourg (ftp.cdsarc.u-strasbg.fr) and on the site of the Main Astronomical Observatory (http://www.mao.kiev.ua).  相似文献   

2.
We present the technique we used to compile a catalog of about 61 000 local stars brighter than K s = 8.2 m which were identified as most likely red clump candidates on the basis of their reduced proper motions in the K s band. The catalog was compiled from the combined Tycho-2 and 2MASS data for the stars with color indices J-K s ranging from 0.5 m to 0.8 m . It includes the equatorial coordinates, the proper motions, the magnitudes B T , V T , J, H, and K s , and the probabilities for the stars to be red clump giants.  相似文献   

3.
Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame. For the most distant (d≈900 pc) Tycho-2 and UCAC2 stars, the mean rotation around the Galactic y axis has been found to be M 13 ? =?0.37±0.04 mas yr?1. The proper motions of UCAC2 stars with magnitudes in the range 12–15m are shown to be distorted appreciably by the magnitude equation in μα cos δ, which has the strongest effect for northern-sky stars with a coefficient of ?0.60±0.05 mas yr?1 mag?1. We have detected no significant effect of the magnitude equation in the proper motions of UCAC2 stars brighter than ≈11m.  相似文献   

4.
The absolute proper motions of about 275 million stars from the Kharkov XPM catalog have been obtained by comparing their positions in the 2MASS and USNO-A2.0 catalogs with an epoch difference of about 45 yr for northern-hemisphere stars and about 17 yr for southern-hemisphere stars. The zero point of the system of absolute proper motions has been determined using 1.45 million galaxies. The equatorial components of the residual rotation vector of the ICRS/UCAC2 coordinate system relative to the system of extragalactic sources have been determined by comparing the XPM and UCAC2 stellar proper motions: ω x,y,z = (−0.06, 0.17, −0.84) ± (0.15, 0.14, 0.14) mas yr−1. These parameters have been calculated using about 1 million faintest UCAC2 stars with magnitudes R UCAC2 > 16 m and J > 14 m . 7, for which the color and magnitude equation effects are negligible.  相似文献   

5.
The PPM catalogue contains the most complete and accurate information concerning positions, proper motions and some astrophysical data for practically all stars (about 379000) down to 10m-11m over the whole sky. The systems and rms errors of the PPm positions, proper motions, stellar magnitudes and spectral classification are studied by comparison with catalogues of stellar characteristics and on the basis of the PPM data itself. The residual errors of stellar data in the PPM catalogue are small and/or they can be determined and eliminated.  相似文献   

6.
A study of four open clusters on Tautenburg Schmidt plates in the direction to the Galactic Centre (l = 17.0°, b = +0.8°) is presented. In a field of 8.95 square degrees proper motions and B, V magnitudes were determined for about 36 500 stars up to the limiting magnitudes B = 17m.9, V = 16m.8. For stars brighter than B = 16m an accuracy of about 3 mas/year has been estimated for proper motions. The rms errors of stellar magnitudes and (B—V) colours is about 0.1 mag. There are two open clusters already known in this sky area: Trumpler 32 (C 1814-133) and NGC 6611 (C 1816-138). By the inspection of the plates two additional anonymous clusters were identified near the double star ADS 11285 or BD −14°5014 (C 1819-146) and near the star BD −14°5016 (C 1820-146). The cluster membership determination was carried out using information on spatial and proper motion distributions of stars in the field. The colour-magnitude diagrams up to the limiting stellar magnitude were constructed. For each cluster interstellar extinction AV, diameters of the core and corona, ages and spatial velocity components (V, W) relative to the LSR in the Y, Z-galactic directions were derived. The distances to the clusters were obtained to 1720 pc, 2260 pc, 2130 pc and 2130 pc for Trumpler 32, NGC 6611, C 1819-146 and C 1820-146, respectively. All clusters are situated in the Sagittarius-Carina spiral arm. Their spatial location confirms the assumption that galactic spiral arms are close to logarithmic spirals with a characteristic angle of about 20 degrees.  相似文献   

7.
The positions and proper motions of the stars from the XC1 catalog are compared with the data of other modern catalogs of stars and extragalactic objects. We demonstrate that the XC1 system is free from significant systematic errors. The external error in the proper motions of the stars fainter than 15 m is estimated at 3–5 mas/yr, depending on magnitude.  相似文献   

8.
The catalog of equatorial coordinates α and δ and B-magnitudes of stars of the northern sky (from–4° to +90°) was created as a part of the FON project at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The data accumulated in the Joint Digital Archive of the Ukrainian Virtual Observatory were used. The total number of processed plates is 2260. Astronegatives were digitized with Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL scanners in the 1200 dpi scanning mode. The majority of plates have a size of 30 × 30 cm (13000 × 13000 pixels). The catalog contains the data on 19451751 stars and galaxies with B ≤ 16.5m at the epoch of 1988.1. The coordinates of stars and galaxies were obtained in the Tycho-2 reference system, and B-magnitudes were determined in the system of photoelectric standards. The mean internal errors of the catalog are σαδ = 0.23″ and σB = 0.14m for all objects or σαδ = 0.10″ and σB = 0.07m for stars in the B = 7m–14m range. The convergence between the catalog and Tycho-2 is characterized by the following values: 0.06′′ and 0.15m. The mean-square difference in coordinates from the catalog and from UCAC-4 is σαδ = 0.30′′ (18 742 932 objects, or 96.36% of stars and galaxies, were cross-identified).  相似文献   

9.
The PUL2 catalog has been photographically compiled in Pulkovo according to Deutch's plan. The catalog contains the mean coordinates of stars in the ICRS system at epoch J2000.0 and their original absolute proper motions. The photographic observations were performed with a normal astrograph. The first and second epochs of the photographic plates are 1937–1965 and 1969–1986, respectively. The PUL2 fields uniformly cover the northern sky. The mean difference between the epochs is 24 years. At least three pairs of plates are available for each field. There are one-hour and five-minute exposures on all plates. One pair of plates was taken with a diffraction grating. Only bright reference stars were measured on the pairs of plates with a grating. Based on a reduction model with six constants and using faint (\(15\mathop m\limits_. 2\)) reference stars, we determined the relative proper motions of the stars. We used ～700 galaxies for absolutization. The mean errors in the relative proper motions of the PUL2 stars are 5.5 mas yr?1 (milliarcseconds per year) in μα cos δ and 5.9 mas yr?1 in μδ. When using galaxies, the mean absolutization error is 7.9 mas yr?1 in both coordinates. By comparing the PUL2 and HIPPARCOS catalogs, we determined the components of the residual rotation vector ω for HIPPARCOS relative to the extragalactic (equatorial) coordinate system: ωx,y,z=(?0.98, ?0.03, ?1.66)±(0.47, 0.38, 0.42) mas yr?1. The mean error of one absolute proper motion of a bright PUL2 star in external convergence is 9 mas yr?1 in both coordinates.  相似文献   

10.
The computational algorithm to determine the the proper motions of Zirconium stars on the basis of catalogues “Carte du Ciel” and on the recent photographic observations carried out with the 70cm Abastumani meniscus telescope is presented. It allowed to determine the proper motions of 288 stars in the region around α Per with a rms error of ± 0,004 arcsec/yr. Applying the method proper motions of 74 Zirconium stars and 146 control stars have been obtained. The error of proper motions obtained for the North Zone (δ > −2°) 109 AGK3 control stars is ± 0.006 arcsec/yr. On the basis of proper motins absolute magnitudes were separately calculated for the MCLPZS and LASZS. For the MCLPZS the average absolute visual magnitude at maximum, corresponding to the mean period of P = 350 days, equals −3ϕm.9. For the LASZS the mean absolute visual magnitude, corresponding to the apparent median ones equals −1ϕm.9. Low luminosity (Mv = −1ϕmϕ9) Zirconium stars escape rather far (at a distance of up to 2 kpc) to the South from the Galactic plane into the region l ∼ 240 – 260°, where its assumed to be a connection with the Large Magellanic Cloud (LMC) begins to appear. Low luminosity Zirconium stars are weakly correlated with position of the Galaxy spiral arms. The MCLPZS show a somewhat other distribution.  相似文献   

11.
Based on the most complete list of the results of an individual comparison of the proper motions for stars of various programs common to the Hipparcos catalog, each of which is an independent realization of the inertial reference frame with regard to stellar proper motions, we redetermined the vector ω of residual rotation of the ICRS system relative to the extragalactic reference frame. The equatorial components of this vector were found to be the following: ωx=+0.04±0.15 mas yr?1, ωy=+0.18±0.12 mas yr?1, and ωz=?0.35±0.09 mas yr?1.  相似文献   

12.
The catalog of equatorial coordinates α and δ and B-magnitudes of stars has been created at the Main Astronomical Observatory, National Academy of Sciences of Ukraine (MAO NASU), for the circumpolar region (from 58° to 90°) of the Northern Sky Survey (FON) project within the work on the rational use of resources accumulated in the JDA (Joint Digital Archive) of the Ukrainian Virtual Observatory (UkrVO). The total number of processed plates is 477. The plates were digitized with the using Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL scanners (scanning mode was 1200 dpi, the linear size of plates was 30 × 30 cm or 13000 × 13000 px). The catalog includes 1 975 967 stars and galaxies with B of up to 16.5 m as of the epoch of 1985.28. The coordinates of stars and galaxies were obtained in the Tycho-2 reference system and B-magnitudes were obtained in the system of photoelectric standards. The internal errors of the catalog for all the objects are σαδ = 0.23′′ and σ B = 0.12 m , and those for stars of the B range from 8 m –14 m , 0.11′′ and 0.06 m , respectively. The convergence between the calculated and reference positions is σαδ = 0.06′′ (for 171124 stars from Tycho-2), and that between the photoelectric stellar B-magnitudes is σ B = 0.15m (for 5130 stars). The external error from the comparison with UCAC-4 are σαδ = 0.33′′ (1928367 stars and galaxies have been cross identified).  相似文献   

13.
A study of four open clusters in the direction of the Galactic anticentre (l = 186°, b = +2°) is presented. In a field of 8.32 square degrees proper motions and B magnitudes for about 79 000 stars down to 19.5 were determined on Tautenburg Schmidt plates. For more than 15 500 of them U magnitudes down to 17.3 could be obtained. Additionally, OCA Schmidt plates were used to determine V, R magnitudes in a larger field of 24.45 square degrees for 271 000 stars down to V = 18.2. For stars brighter than V = 15.5 an accuracy of about 1.5 mas/yr has been estimated for proper motions. The rms errors of stellar magnitudes and colour indices are 0.09 – 0.12 mag. Several open clusters have been already known in this direction of the sky, e.g. NGC 2168 or M 35 (C 0605+243), NGC 2158 (C 0604+241) and IC 2157 (C 0601+240). Inspecting the plates and analysing the colour-magnitude diagrams and published data, we could identify an additional anonymous cluster C 0605+242 with a projection on the sky near the centre of M 35 but at a larger distance from the Sun. The cluster membership determination was carried out using information on spatial and proper motion distributions of stars in the field. The colour-magnitude diagrams were derived down to the limiting stellar magnitude. For each cluster the interstellar extinction Av, the diameters of the core and corona, the ages and spatial velocity components (V,W) relative to the LSR in the Y,Z – Galactic directions were determined. The distances to the clusters of 960 pc, 2 600 pc, 2 520 pc and 3 700 pc were obtained for M 35, IC 2157, C 0605+242 and NGC 2158. They show the loci of the clusters in the Local and Perseus spiral arms and at external border of Perseus arm, respectively.  相似文献   

14.
The processing of the plates of the Kitab part of the FON project has been completed. In total, 1963 plates were processed. The catalog of equatorial coordinates α, δ, and B-magnitudes for 13 413268 stars and galaxies up to B ≤ 17.5 m for the epoch 1984.97 is compiled. The Epson Expression 10000XL scanner with a 1200 dpi scanning mode and a plate size of 30 × 30 cm or 13000 × 13000 pel was used to digitize astronegatives. Coordinates of stars and galaxies are obtained in the Tycho-2 catalog system and B-magnitudes are obtained in the photovoltaic system. The catalog internal accuracy for all objects is σα,δ = 0.23" and σ B = 0.15 m (for stars in the range B = 5 m …14 m , errors are σα,δ = 0.085" and σ B = 0.054 m ) for equatorial coordinates and stellar B-magnitudes, respectively. Convergence between the calculated and reference positions is σα,δ = 0.042", and convergence between photoelectric B-magnitudes is σ B = 0.16 m . Coordinate errors with respect to the UCAC-4 catalog are σα,δ = 0.26" (9892697 or 73.75% of stars and galaxies were identified).  相似文献   

15.
Five sky areas about the radio sources ICRS 1254+571, ICRS 1345+125, ICRS 1641+399, ICRS 1732+389, and ICRS 1807+698 were observed with the aim to identify reliably the extragalactic radio sources in these areas with bright infrared objects and objects in the optical range. The test CCD observations were made in the U, V, and R bands of the Johnson system with the 2-meter telescope of the Terskol Peak Observatory (North Caucasus, Russian Federation). The U, V, and B magnitudes and the equatorial coordinates α and δ in the USNO-A2.0 catalog system were determined for objects down to V ≈ 23m in 8.5′ × 8.5′ areas, and these objects were identified with stars and infrared objects in the 2MASS catalog. The CCD image processing realized within the MIDAS/ROMAFOT program package on the basis of a new method for flat-field elimination is briefly described.  相似文献   

16.
We perform a kinematic analysis of the Hipparcos and TRC proper motions of stars by using a linear Ogorodnikov-Milne model. All of the distant (r>0.2 kpc) stars of the Hipparcos catalog have been found to rotate around the Galactic y axis with an angular velocity of M 13 ? =?0.36±0.09 mas yr?1. One of the causes of this rotation may be an uncertainty in the lunisolar precession constant adopted when constructing the ICRS. In this case, the correction to the IAU (1976) lunisolar precession constant in longitude is shown to be Δp1=?3.26±0.10 mas yr?1. Based on the TRC catalog, we have determined the mean Oort constants: A=14.9±1.0 and B=?10.8±0.3 km s?1 kpc?1. The component of the model that describes the rotation of all TRC stars around the Galactic y axis is nonzero for all magnitudes, M 13 ? =?0.86±0.11 mas yr?1.  相似文献   

17.
The stellar composition of the Tycho-2 Catalogue in the range B-V = 0· m 75–1· m 25 has been reproduced through Monte Carlo simulations. For young and old stars of the red giant clump (RGC), the red giant branch, subgiants, red dwarfs, and thick-disk giants, we have specified the distributions in coordinates, velocities, B-V, and M V as a function of B-V and calculated their reduced proper motions, photometric distances from the (B-V)-M V calibration, and photoastrometric distances from the reduced proper motion-M V calibration. Our simulations have shown the following: (1) a sample of thin-disk giants within 500 pc with an admixture of less than 10% of other stars can be produced; (2) a sample of dwarfs within 100 pc almost without any admixture of other stars can be produced; (3) the Local Spiral Arm affects the RGC composition of any magnitude-limited catalog in favor of giants younger than 2 Gyr; (4) the samples produced using reduced proper motions can be used for kinematic studies, provided that the biases of the quantities being determined are simulated and taken into account; (5) the photometric distances correlate with the photoastrometric ones because of the correlation between the proper motion and magnitude; (6) the photometric distances are closer to the true ones for the red giant branch and red dwarfs as the categories of stars with a clear (B-V)-M V relation, while the photoastrometric distances are closer to the true ones for the RGC, subgiants, and thick-disk giants; (7) the calculated distances differ systematically from the true ones, but they can be used to analyze the three-dimensional distribution of stars. Our simulations confirm the validity of our previous selection of RGC stars from Tycho-2.  相似文献   

18.
Astroplates acquired in the course of the Photographic Survey of the Northern Sky project (abbreviated as FON) were scanned at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (MAO NASU). For this, the Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL scanners were used. From 1600 plates of the total amount, the rectangular coordinates of stars were obtained. After the astrometric reduction, a catalog of the equatorial coordinates and brightness for more than 15 million stars was built up. The mean-squared errors in positions and B magnitudes of the stars in the catalog (from–2° to 90° by declination) mainly depend on the position in a plate, the overlapping multiplicity (that may reach 8), and the stellar magnitude. These errors estimated by internal convergence are within the limits of 0.1′′–0.4′′ and 0.05–0.2 m for the coordinates and stellar magnitudes, respectively.  相似文献   

19.
Using modern astronomical databases, particularly 2MASS All - Sky Data Release Point Source Catalog and USNO-B1.0 catalog, we investigate the properties of about 840 FBS red stars in order to clarifiy their nature. We use and analyse their JHK 2MASS photometry, together with the R-band magnitudes and the proper motions provided by USNO - B1.0. Approximately 70% of all objects appear to be Asymptotic Giant Branch stars, 18% are giants, and close to 12% are objects with detectable proper motions, allowing to consider them as dwarf M-type stars. When plotted in a J - K versus R - K colour-colour diagram, one finds that objects with proper motions are well separated into a narrow belt.__________Published in Astrofizika, Vol. 48, No. 3, pp. 383–392 (August 2005).  相似文献   

20.
We present the results of our comprehensive study of the Galactic open star cluster NGC 6866. The positions of stars in the investigated region have been obtained with the “Fantasy” automatic measuring machine from 10 plates of the normal astrograph at the Pulkovo Astronomical Observatory. The size of the investigated field is 40′ × 40′, the limiting magnitude is B ∼ 16· m 6, and the maximum epoch difference is 79 yr. For 1202 field stars, we have determined the relative proper motions with an rms error of 2.5 mas yr−1. Out of them, 423 stars may be considered cluster members with a probability P > 70% according to the astrometric criterion. Photometric diagrams have been used as an additional criterion. We have performed two-color BV CCD photometry of stars with the Pulkovo ZA-320M mirror astrograph. The U magnitudes from the literature have also been used to construct the two-color diagrams. A total of 267 stars have turned out to be members of NGC 6866 according to the two criteria. We present refined physical parameters of the cluster and its age estimate (5.6 × 108 yr). The cluster membership of red and blue giants, variable, double, and multiple stars is considered. We have found an almost complete coincidence of the positions of one of the stars in the region (a cluster nonmember) and a soft X-ray source in the ROSAT catalog. The “Fantasy” automatic measuring machine is described in the Appendix.  相似文献   

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