Search

We present the results of determining the coordinates of the vertices of various stellar systems, the centroids of which are located in the Galactic plane. To do this, the positions, parallaxes, proper motions, and radial velocities of red giants and subgiants contained in the $Gaia$~DR3 catalogue have been used. When determining the components of the deformation velocity tensors in local coordinate systems, we found the coordinates of the vertices of the stellar systems under study. It turned out that there is a complex dependence of vertex deviations $l_{xy}$ in Galactocentric cylindrical ($R, \theta$) and Galactic rectangular ($X,Y$) coordinates. Based on the approach proposed in this paper, heliocentric distances to vertices have been determined for the first time. The results obtained show that in addition to the fact that the angular coordinates of the Galactic center and the vertices of stellar systems do not coincide, their heliocentric distances do not coincide as well. This presumably indicates that there are structures in the Galaxy that noticeably affect its axisymmetry., Comment: 10 pages, 14 figures, 1 tables

We present the results of a kinematic analysis of red giants and subgiants whose centroids are in the plane of our Galaxy. For this, the positions, parallaxes, proper motions, and radial velocities of these stars from the $Gaia$ EDR3 catalog were used. We applied two approaches to obtain kinematic parameters. The first approach -- solving the equations of the Ogorodnikov--Milne model with respect to 12 kinematic parameters -- is generally accepted, but has a number of disadvantages. The second approach developed by us is to find the components of galactocentric centroid's velocity and their partial derivatives with respect to coordinates directly from differential equations for the stellar velocity field. To calculate the kinematic parameters by the methods mentioned above, same stellar samples were used. From these samples spherical regions with a radius of 1 kpc were selected, the centers of which were located strictly in the Galactic mid-plane at the nodes of the coordinate grid ($x_{gal}$, $y_{gal}$) of a rectangular Galactocentric coordinate system with step 100 pc. The region of the Galaxy under study occupies the coordinate interval $115^\circ < \theta < 245^\circ$, 0 kpc$ < R < $16 kpc, -1 kpc$ < z < $1 kpc. We show the behavior of local kinematic parameters as well as global parameters such as the circular velocity of stars as a function of galactocentric coordinates. For the first time, the components of centroids' spatial velocities and all their partial derivatives as well as their behavior as a function of galactic coordinates have been derived. The behavior of the $\partial V_R/\partial \theta$ and $\partial V_\theta/\partial \theta$ parameters as a function of galactic coordinates has been derived for the first time., Comment: 11 pages, 15 figure

We aim at analysis of kinematics of main-sequence stars from the GaiaDR2 and PMA catalogues as well as comparison of kinematic parameters derived from their proper motions. We decompose the stellar velocity field on to a set of vector spherical harmonics (VSH), and, using the relations between the decomposition coefficients and the Ogorodnikov–Milne (O–M) model parameters, calculate the latter. The method of VSH allowed to detect all systematic constituents present in the GaiaDR2 and PMA stellar velocity fields. We notice incompleteness of the O–M model, discuss the kinematic parameters derived within its framework, as well as significant decomposition coefficients that do not have analogues within this model. For separate analysis of the kinematic parameters in the Northern and Southern Galactic hemispheres, we apply the decomposition on to a set of zonal VSH (ZVSH). Modelling the stellar velocity field allowed to confirm the causes of some significant beyond-the-model harmonics. Based on stellar proper motions from the Gaia DR2 and PMA catalogues, we confirm the previous conclusion that the values of ω1 and $M^+_{23}$ O–M model parameters derived in the Northern and Southern Galactic hemispheres have opposite signs. This fact takes place due to a vertical gradient of the linear rotation velocity about the Galactic centre. We estimate influence of the vertical gradient on the value of solar velocity component Y⊙. We confirm that the beyond-the-model coefficients t211 and s310 are caused by the vertical gradient as well.

We present the results of the kinematic investigations carried out with the use of spatial velocities of red giants and subgiants contained in the Gaia EDR3 catalogue. The 12 kinematic parameters of the Ogorodnikov–Milne model have been derived for stellar systems with radii of 0.5 and 1.0 kpc, located along the direction of the Galactic Centre–the Sun–the Galactic anticentre within the range of Galactocentric distances R = 0–8–16 kpc. By combining some of the local parameters, the information related to the Galaxy as a whole has been received in the distance range of 4–12 kpc, in particular the circular velocity curve of red giant and subgiant centroids, its slope, and velocity gradients. We show that when using this approach, there is an alternative possibility to infer the behaviour of the circular velocity curve of red giant and subgiant centroids and its slope without using the Galactocentric distance R⊙. The kinematic parameters derived within the solar vicinity of 1 kpc radius are in good agreement with those given in the literature.

The plan of the photographic survey of thenorthern sky (FON) was proposed in 1976 in Golosiiv ob-servatory (now MAO NAS of Ukraine) by I. Kolchinskyand A. Onegina. The final project of the Compiled FONACcatalog (FON Astrographic Catalog) is based on the digitaldata of photographic plates exposed at four observatories.They are MAO NAS of Ukraine (Kyiv, Ukraine), Kitabastronomical observatory (Tashkent, Uzbekistan), Hissarastronomical observatory (Dushanbe, Tajikistan), and Bal-done observatory (Latvia)). The total amount of plates is5700. The result is expected to be the catalog of positionsand B-magnitudes of stars covered the declination areafrom -20 to 90 degrees. The estimated mean epoch of thecatalog is ~1987. The limiting B-magnitude is ~17.5 m . Thereference system for positions is Tycho-2. B-magnitudesare being obtained in the system of photoelectric standards.The resulted data of photometric reduction are corrected forthe photometric color equation in B magnitudes. The com-plement for the photometric content of the catalog is U andV magnitudes of stars being obtained from the processingof 5400 plates from the glass collection of 1.2 m Schmidttelescope in Baldone. Photometric data of bright stars withV < 8.5 m U, B,V magnitudes cannot be obtained from pho-tographic material, so those objects will gain photometricdata from photoelectric catalogs. The catalog will be com-plemented with proper motions from GAIA., План фотозйомки північного неба(ФОН) був запропонований у 1976 році в Голосіївськійобсерваторії (нині МАО НАН України) І. Колчинськимта А. Онєгіною. Остаточний проект каталогу складено-го FONAC (FON Astrographic Catalog) ґрунтується нацифрових даних фотопластинок, експонованих у чоти-рьох обсерваторіях: МАО НАН України (Київ, Украї-на), Кітабська астрономічна обсерваторія (Ташкент,Узбекистан), Гіссарська астрономічна обсерваторія(Душанбе, Таджикистан) та Балдонська обсерваторія(Латвія). Загальна кількість пластинок – 5700. В резуль-таті повинен бути створений каталог положень і B-величин зірок, який охоплюватиме область неба від -20до 90 градусів DEC. Орієнтовна середня епоха каталогу– 1987 рік. Гранична В-величина становить ~ 17,5 m .Опорною системою є Tycho-2. В-величини визначають-ся у системі фотоелектричних стандартів. Отриманідані фотометричної редукції коригуються за фотомет-ричне рівняння кольору у величинах B. Доповненнямдля фотометричного вмісту каталогу є величини U та Vзірок, отримані при обробці 5400 пластинок 1,2 м теле-скопа Шмідта в Балдоне. Фотометричні дані яскравихзірок з величиною V

The paper discusses the construction of characteristic curves for various astronegatives with a single exposure. Particular attention is paid to the question of extrapolation of the characteristic curve for the region of the weakest stars in the absence of standards. A new method for constructing an individual characteristic curve for digitized films and plates in the UBVR system has been proposed and implemented. The processing of frames of digitized plates and films with sky areas is car- ried out using LINUX/MIDAS/ROMAFOT software tools. ROMAFOT application allows us to extract astro- metric rectangular coordinates X,Y and photometric char- acteristics such as instrumental photometric magnitudes m, FWHM, and the intensity in the center of the star im- age I c for all fixed objects on each astronegative. For all frames, the connection between instrumental photometric values m with stellar magnitudes in any system (Johnson UBVR, Tycho-2 or GAIA catalogs, etc.) is not linear and multipurpose. It is presented as the characteristic curve for each astronegative. Currently, the determination of U, B, V, R magnitudes of stars and other space objects is in pro- gress for astronegatives with the single exposure obtained in the frameworks of selected observational projects.

We investigate the systems of proper motions of stars in the ground-based catalogues HSOY, UCAC5, GPS1, and PMA derived by combining with the Gaia DR1 space data. Assuming the systematic differences of stellar proper motions of two catalogues to be caused by the mutual solid-body rotation and glide of the coordinate systems produced by the data of the catalogues under comparison, we analyse the components of the mutual rotation vector and displacement of the origins of these systems. The equatorial components of the vector of mutual rotation velocity of the compared coordinate systems, as well as velocities of the mutual displacement of their origins, vary within the range from 0.2 to 2.9 mas yr−1, were derived from a comparison of proper motions of the sources that are common for Gaia EDR3 and the TGAS, UCAC5, HSOY, GPS1, and PMA catalogues, respectively. The systematic errors of proper motions of stars in the HSOY, GPS1, PMA, and Gaia EDR3 catalogues in the range of faint stellar magnitudes were estimated by analysing the formal proper motions of extragalactic objects contained in these catalogues. The coordinate system realized by the Gaia EDR3 data at the level of

We have developed the dynamical model of a clumpy torus in an active galactic nucleus (AGN) and compared to recent ALMA observations. We present $N$-body simulations of a torus in the field of a supermassive black hole (SMBH), made of up to $N=10^5$ gravitationally interacting clouds. As initial conditions, we choose random distributions of the orbital elements of the clouds with a cut-off in the inclination to mimic the presence of wind cones produced at the early AGN stage. When the torus reaches an equilibrium, it has a doughnut shape. We discuss the presence of box orbits. We have then constructed the velocity and velocity dispersion maps using the resulting distributions of the clouds at equilibrium. The effects of torus inclination and cloud sizes are duly analyzed. We discuss the obscuration effects of the clouds using a ray tracing simulation matching the model maps to ALMA resolution. By comparing the model with the observational maps of NGC 1068 we find that the SMBH mass is $M_\text{smbh}=5\times 10^6 M_\odot$ for the range of the torus inclination angles $45^\circ - 60^\circ$. We also construct the velocity dispersion maps for NGC 1326 and NGC 1672. They show that the peaks in the ALMA dispersion maps are related to the emission of the torus throat. Finally, we obtain the temperature distribution maps with parameters that correspond to our model velocity maps for NGC 1068. They show stratification in temperature distribution with the shape of the high temperature region as in the VLTI/MIDI map., 16 pages, 19 figures, 1 table, accepted for publication in MNRAS

We present the results of identification of extragalactic objects within cross-matching result of the two photometric catalogues, AllWISE and Pan-STARRS DR1. To separate galaxies and quasars from stars, we constructed a machine learning model, trained on photometric information from optical and infrared wavelength ranges. The model was based on three essential procedures: construction of the autoencoder artificial neural network, separation of galaxies and quasars from stars with Support Vector Machine (SVM) classifier, and cleaning the AllWISE\(\times \)PS1 sample from sources with unusual colour indexes with one-class SVM. As a training sample, we used a set of spectroscopically confirmed sources from Sloan Digital Sky Survey Data Release 14. In the result of applying the classification model to the AllWISE\(\times \)PS1 sample, we created catalogue, containing 40 million extragalactic objects, and covering 3/4 of the celestial sphere up to g=\(23^m\). A number of tests to examine the classification quality using different methods, namely data from spectroscopic surveys, and astrometric examination, are in agreement with each other. Tests indicate high purity (\(\sim 98.0\%\)) and completeness (\(>98\%\)) of resulting catalogue at the faint end of magnitude range; classification quality still retains acceptable levels of \(70\%\) for purity and \(97\%\) for completeness for the brightest and faintest parts of g magnitude range.

We present the results of applying deep convolutional neural network to the images of redshift-limited ( z < 0 . 1) sample of ∼ 300000 galaxies from the SDSS DR9. We aimed to classify galaxies into the two classes: Elliptical and Spiral. To create the training sample, we used a set of ∼ 6000 galaxies from our previous work with visually inspected morphologi- cal types, and also added 80000 well-confirmed galaxies from Galaxy Zoo 2 dataset, that were also classified visually. With a given sample of ∼ 86000 galaxies, we used the deep neural network, namely Xception, to provide a classification of g-r-i composite images (25 arcsec in each axis in size) of galaxies. Keeping in the mind a relatively small training dataset, we provided the data augmentation (horizontal and vertical flips, random shifts on ± 10 pixels , and rotations within 180 degrees), that was randomly applied to the images during learning. The data augmentation is a key technique within our algorithm to display the variative nature of the observed galaxies, and avoid overfitting problem. We compared our classification result with the Support Vector Machine (SVM) classification performed on the SDSS photometric data (absolute magnitudes, colour indices, inverse concentration index, ratios of semiaxes, etc.), and proposed a method to learn the benefits from both approaches (Deep Learning and photometric classification). We show the common mistakes of both algorithms, and propose to stack these two approaches to block these mistakes, with a main goal to increase the overall classification quality of SDSS galaxies.

We present a catalogue that contains about 420 million absolute proper motions of stars. It was derived from the combination of positions from Gaia DR1 and 2MASS, with a mean difference of epochs of about 15 yr. Most of the systematic zonal errors inherent in the 2MASS Catalogue were eliminated before deriving the absolute proper motions. The absolute calibration procedure (zero-pointing of the proper motions) was carried out using about 1.6 million positions of extragalactic sources. The mean formal error of the absolute calibration is less than 0.35 mas yr−1. The derived proper motions cover the whole celestial sphere without gaps for a range of stellar magnitudes from 8 to 21 mag. In the sky areas where the extragalactic sources are invisible (the avoidance zone), a dedicated procedure was used that transforms the relative proper motions into absolute ones. The rms error of proper motions depends on stellar magnitude and ranges from 2–5 mas yr−1 for stars with 10 mag

We derive and compare kinematic parameters of the Galaxy using the PMA andGaiaTGAS data. Two methods are used in calculations: evaluation of the Ogorodnikov-Milne model (OMM) parameters by the least square method (LSM) and a decomposition on a set of vector spherical harmonics (VSH). We trace dependencies on the distance of the derived parameters including the Oort constants A and B and the rotational velocity of the GalaxyVrotat the Solar distance for the common sample of stars of mixed spectral composition of the PMA and TGAS catalogues. The distances were obtained from the TGAS parallaxes or from reduced proper motions for fainter stars.The A, B andVrotparameters derived from proper motions of both catalogues used show identical behaviour but the values are systematically shifted by about 0.5 mas/yr.The Oort B parameter derived from the PMA sample of red giants shows gradual decrease with increasing the distance while the Oort A has a minimum at about 2 kpc and then gradually increases.As for models chosen for calculations, first, we confirm conclusions of other authors about the existence of extra-model harmonics in the stellar velocity field. Secondly, not all parameters of the OMM are statistically significant, and the set of parameters depends on the stellar sample used.

In this paper we presented the new method for selection of the reference stars to carry out the astrometric reduction of sky images. The presented algorithm takes into account the main features of the formation of astronomical measurements in CCD-frames. Also to improve the accuracy and speed up processing the proposed method includes verification of candidates to the reference stars and excluding them if needed based on the specific rule. This computational method was successfully tested in the software for automated search and detection of asteroids, comets and satellites in a series of CCD-frames within the CoLiTec project. The comparative analysis of the accuracy of astronomical measurements of the Solar System small bodies by CoLiTec and Astrometrica software was performed as a result of research. The developed method for selection of the reference stars provides the high accuracy of measurements of celestial objects in digital images.

In this paper we presented the new algorithm for astrometric reduction of the images received from modern large telescopes with very wide field of view. This algorithm is based on the iterative using of the method of ordinary least squares (OLS) and statistical Student t-criterion. The paper contains information about selecting the appropriate reduction model and system of conditional equations for determination of the reduction model parameters with the aim to solve it using the OLS method. The proposed algorithm also provides the automatic selection of the most probabilistic reduction model. At the first iteration the fifth degree polynomial is used, which provides 21 constant plates. The reduction error from the each iteration is used in the next iteration to eliminate reference objects whose residuals more than three sigma. In the developed algorithm the statistical Student t-criterion of reliability is applied after several iterations of getting rid of the noisy objects. This approach allows us to eliminate almost all systematic errors that are caused by imperfections of the optical system of modern large telescopes. The developed software based on the proposed algorithm was applied to perform the astrometric reduction of all measured positions of objects on the digitized photographic plates of SuperCOSMOS data. The research results showed that the new proposed algorithm allows performing the reduction into the system of reference catalogue with the highest accuracy level.

In this paper we presented the results of cloud computing and analysis of orbital parameters of the satellite fragments that formed by first India anti-satellite (ASAT) missile against a "live" Microsat-R satellite launched by them on January 24, 2019. Based on the cloud computing we calculated the orbital parameters and distribution of impulse values obtained by Microsat-R fragments that were formed after the impact of ASAT missile and tracked by NASA. All results in this paper and detailed analysis of this event are based on the orbital data taken in form of NORAD two-line element (TLE) dataset from space-track.org and by own calculation of the CoLiTec group in EOS Data Analytics using own cloud server. The test parameters were chosen with extreme caution to minimize the hazard of debris after the impact. However, the results of our research showed the significant differences from expected "head-on collision" of rocket with Microsat-R satellite.

In this paper we presented the new algorithm for pixelization of astronomical data in celestial sphere. This algorithm is used for partition and analysis of the large astronomical catalogues that contain data of up to billion objects. The proposed algorithm for pixelization can be applied for indexing of the objects positions in the celestial sphere. This allows the quick search in the large astronomical databases. The search results of indexed objects can be used by different consumers such as robotic telescopes, ground and flying robots that need to guidance, navigate and even to track the situation in celestial sphere. The problems of sphere partition to pixels by different methods are also described in the paper.

This study involves two photometric catalogues, AllWISE and Pan-STARRS Data Release 1, which were cross-matched to identify extragalactic objects among the common sources of these catalogues. To separate galaxies and quasars from stars, we created a machine-learning model that is trained on photometric (in fact, colour-based) information from the optical and infrared wavelength ranges. The model is based on three important procedures: the construction of the autoencoder artificial neural network, separation of galaxies and quasars from stars with a support vector machine (SVM) classifier, and cleaning of the AllWISE × PS1 sample to remove sources with abnormal colour indices using a one-class SVM. As a training sample, we employed a set of spectroscopically confirmed sources from the Sloan Digital Sky Survey Data Release 14. Having applied the classification model to the data of crossing the AllWISE and Pan-STARRS DR1 samples, we created the Northern Extragalactic WISE × Pan-STARRS (NEWS) catalogue, containing 40 million extragalactic objects and covering 3/4 of celestial sphere up to g = 23m. Several independent classification quality tests, namely, the astrometric test along with others based on the use of data from spectroscopic surveys show similar results and indicate a high purity (∼98.0%) and completeness (> 98%) for the NEWS catalogue within the magnitude range of 19.0m < g < 22.5m. The classification quality still retains quite acceptable levels of 70% for purity and 97% for completeness for the brightest and faintest objects from this magnitude range. In addition, validation with external data sets has demonstrated the need for using only those sources in the NEWS catalogue that are outside the zone with the enhanced extinction. We show that the number of quasars from the NEWS catalogue identified in Gaia DR2 exceeds the number of quasars previously identified in Gaia DR2 with the use of the AllWISEAGN catalogue. These quasars may be used in future as an additional sample for testing and anchoring the Gaia Celestial Reference Frame.

We present new fully-automatic classification model to select extragalactic objects within astronomical photometric catalogs. Construction of the our classification model is based on the three important procedures: 1) data representation to create feature space; 2) building hypersurface in feature space to limit range of features (outliers detection); 3) building hyperplane separating extragalactic objects from the galactic ones. We trained our model with 1.7 million objects (1.4 million galaxies and quasars, 0.3 million stars). The application of the model is presented as a photometric catalog of 38 million extragalactic objects, identified in the WISE and Pan-STARRS catalogs cross-matched with each other.

In this paper we presented the algorithm designed to efficient coordinate cross-match of objects in the modern massive astronomical catalogues. Preliminary data sort in the existed catalogues provides the opportunity for coordinate identification of the objects without any constraints with the storage and technical environment (PC). Using the multi-threading of the modern computing processors allows speeding up the program up to read-write data to the storage. Also the paper contains the main difficulties of implementing of the algorithm, as well as their possible solutions.

In this paper we presented the modified algorithm for astrometric reduction of the wide-field images. This algorithm is based on the iterative using of the method of ordinary least squares (OLS) and statistical Student t-criterion. The proposed algorithm provides the automatic selection of the most probabilistic reduction model. This approach allows eliminating almost all systematic errors that are caused by imperfections in the optical system of modern large telescopes.

Based on the Ogorodnikov-Milne model, we analyze the proper motions of XPM2, UCAC4 and PPMXL stars. To estimate distances to the stars we used the method of statistical parallaxes herewith the random errors of the distance estimations do not exceed 10%. The method of statistical parallaxes was used to estimate the distances to stars with random errors no larger than 14%. The linear solar velocity relative to the local standard of rest, which is well determined for the local entroid (d 150 p), was used as a reference. We have established that the model component that describes the rotation of all stars under consideration about the Galactic Y axis differs from zero. For the distant (d < 1000 pc) PPMXL and UCAC4 stars, the mean rotation about the Galactic Y axis has been found to be M-13 = -0.75± 0.04 mas yr-1. As for distances greater than 1 kpc M-13derived from the data of only XPM2 catalogue becomes positive and exceeds 0.5 mas yr-1. We interpret this rotation found using the distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame., Based on the Ogorodnikov-Milne model, we analyze the proper motions of XPM2, UCAC4 and PPMXL stars. To estimate distances to the stars we used the method of statistical parallaxes herewith the random errors of the distance estimations do not exceed 10%. The method of statistial parallaxes was used to estimate the distanes to stars with random errors no larger than 14%. The linear solar veloity relative to the local standard of rest, which is well determined for the loal entroid (d 150 p), was used as a referene. We have established that the model component that describes the rotation of all stars under consideration about the Galactic Y axis differs from zero. For the distant (d < 1000 pc) PPMXL and UCAC4 stars, the mean rotation about the Galactic Y axis has been found to be M− 13 = -0.75±0.04 mas yr−1 . As for distances greater than 1 kpc M− 13 derived from the data of only XPM2 catalogue becomes positive and exceeds 0.5 mas yr−1 . We interpret this rotation found using the distant stars as a residual rotation of the ICRS/Tycho- 2 system relative to the inertial reference frame, Based on the Ogorodnikov-Milne model, we analyze the proper motions of XPM2, UCAC4 and PPMXL stars. To estimate distances to the stars we used the method of statistical parallaxes herewith the random errors of the distance estimations do not exceed 10%. The method of statistial parallaxes was used to estimate the distanes to stars with random errors no larger than 14%. The linear solar veloity relative to the local standard of rest, which is well determined for the loal entroid (d 150 p), was used as a referene. We have established that the model component that describes the rotation of all stars under consideration about the Galactic Y axis differs from zero. For the distant (d < 1000 pc) PPMXL and UCAC4 stars, the mean rotation about the Galactic Y axis has been found to be M− 13 = -0.75±0.04 mas yr−1 . As for distances greater than 1 kpc M− 13 derived from the data of only XPM2 catalogue becomes positive and exceeds 0.5 mas yr−1 . We interpret this rotation found using the distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame

This paper reviews the most important components of the national project of the Ukrainian Virtual Observatory (UkrVO). Among them, there is the establishment of a Joint Digital Archive (JDA) of observational data, which has been obtained at Ukrainian observatories since the 1890s, including an astronegative JDA (more than 200 thousand plates). Since this task requires VO-oriented software, such issues as content verification software, integrity and administration of the JDA, compliance of image formats with the IVOA standards, and photometric and astrometric calibration of images are considered as the most important directions of software development, which carried out by members of the UkrVO. The scientific projects using local data archives of the UkrVO are discussed, namely: an analysis of a long observational series of active galactic nuclei, the study of solar flares and solar active regions based on spectral observational archives, research and discovery of variable stars, and the study of stellar fields in the vicinity of gamma-ray bursts. Particular attention is devoted to the CoLiTec Program that permits us to increase a number of observed solar system bodies and allows us to discover new bodies; for example, the C/2010 (Elenin) and P/2011 N01 comets were discovered using this program at the ISON-NM Observatory. The paper notes the creation of the UkrVO JDA prototype that provides access to the databases of the Main Astronomical Observatory, National Academy of Sciences of Ukraine (MAO NAS of Ukraine); Nikolaev Astronomical Observatory (NAO); and Lvov Astronomical Observatory.

We combined the data from theGaiaDR1 and Two-Micron All Sky Survey (2MASS) catalogues in order to derive the absolute proper motions more than 420 million stars distributed all over the sky in the stellar magnitude range 8 mag < G < 21 mag (Gaia magnitude). To eliminate the systematic zonal errors in position of 2MASS catalogue objects, the 2-dimensional median filter was used. The PMA system of proper motion has been obtained by direct link to 1.6 millions extragalactic sources. The short analysis of the absolute proper motion of the PMA stars Catalogue is presented in this work. From a comparison of this data with same stars from the TGAS, UCAC4 and PPMXL catalogues, the equatorial components of the mutual rotation vector of these coordinate systems are determined.

The final version of the XPM catalogue, created by the authors, contains about 314 million stellar positions and absolute proper motions and covers the whole celestial sphere without gaps in the magnitude range 10 m < B < 22 m . The analysis of stellar positions and proper motions of the XPM catalogue is presented. The coordinate axes, defined by the XPM catalogue, were shown to have an ambiguity of rotation relative to the LQAC quasars and ICRF2 sources less than 0.2 mas yr −1 . It is concluded that the XPM catalogue is the independent realization of the ICRS in the optical and near-infrared wavelengths in the sense of obtaining of proper motions. The absolute proper motions of XPM stars were compared with the similar data from the HCRF modern catalogues. The proper motions of stars in these catalogues were shown to have the appreciable random and systematic errors.

The photometry from 2MASS, UCAC3 and SuperCosmos catalogues together with the proper motions from the Tycho-2, XPM and UCAC3 catalogues are used to select the all-sky samples of 34 white dwarfs, 1996 evolved and 7769 unevolved subdwarfs candidates for R from 9 to 17 magnitude. The samples are separated from the main sequence with admixture less than 10% owing to the detailed analysis of the distribution of the stars in the different color index (CI) vs. reduced proper motion (RPM) diagrams for various latitudes with special attention to the estimation of admixtures in the samples and with Monte-Carlo simulation. It is shown that the XPM and UCAC3 have the same level of proper motion accuracy. Most of the selected stars has at least 6-band photometry with accuracy is proved to be better than 0.2. The multicolor photometry allows us to eliminate some admixtures and reveal some binaries. The empirical calibrations of absolute magnitude versus CI and RPM for Hipparcos stars give us photometric distances and 3D distribution for all the stars. Although the selection method and uneven distribution of the XPM and UCAC3 data provide noticeable biases the preliminary conclusions are made. The subdwarfs show some concentration to the galactic centre hemisphere with voids because of extinction in the Gould belt and galactic plane. Some yet unexplained overdensities of the evolved subdwarfs are seen in several parts of the sky. For 183 stars with radial velocities 3D motion and galactic orbits are calculated. For 56 stars with Fe/H collected from various sources we find the relations of the metallicity with CI, asymmetric drift velocity and orbital eccentricity. It is shown that most unevolved subdwarfs belong to the halo with

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: ��_{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., 11 pages, 1 table, 5 figures

We combined data from the Two-Micron All Sky Survey (2MASS) and USNO-A2.0 catalogues in order to derive the absolute proper motions of about 280 million stars distributed all over the sky excluding a small region near the Galactic Centre, in the magnitude range 12 < B < 19 mag. The proper motions were derived from the 2MASS Point Sources and USNO-A2.0 catalogue positions with a mean epoch difference of about 45 years for the Northern hemisphere and about 17 years for the Southern one. The zero-point of the absolute proper motion frame (the 'absolute calibration') was specified with the use of about 1.45 million galaxies from 2MASS. Most of the systematic zonal errors inherent in the USNO-A2.0 catalogue were eliminated before the calculation of proper motions. The mean formal error of absolute calibration is less than 1 mas yr -1 . The XPM Catalogue will be available via CDS in Strasbourg during 2010. The generated catalogue contains the International Celestial Reference System positions of stars for the J2000 epoch, original absolute proper motions, as well as B, R, J, H and K magnitudes. A comparison of the proper motions obtained in this work with the data of other recent catalogues of quasars was fulfilled.

From a comparison of absolute proper motions of stars from the XPM catalogue with those of the same stars from the PPMXL, UCAC3, Tycho-2 and XC1 catalogues, the equatorial components of the rotation vector of these coordinate systems are determined with respect to the coordinate system specified by positions and proper motions of XPM. These parameters are calculated with the use of about 90 million stars from the UCAC3 catalogue and about 300 million stars from the PPMXL catalogue. It is shown that the Hipparcos Celestial Reference Frame represented by the Tycho-2, PPMXL, UCAC3 and XC1 catalogues has a significant rotation component ωz = (−1.8 ± 0.16) mas yr −1 about the equatorial axis directed to the celestial pole. The result is confirmed by an analysis of the formal proper motions of the extragalactic sources contained in the considered catalogues. We investigate the problem of residual rotation of the Hipparcos/Tycho-2 system with respect to extragalactic objects by comparing the derived absolute proper motions of the XPM stars with those of the stars representing the Hipparcos Celestial Reference Frame system. The accuracy of the solution for this problem strongly depends on the accuracy of the proper motions used. In this case, systematic errors of the data in use are determinative rather than random ones. A correct solution is possible only under the condition that the systematic errors in the absolute proper motions of the XPM stars are eliminated. As was shown in Fedorov et al. (2011, hereafter Paper III), the magnitude equation in the XPM catalogue has been eliminated both in the bright and in the faint parts of the stellar magnitude range, while testing confirms the absence of the system rotation within an accuracy of several tenths of a milliarcsecond. This is a reason to treat the system of the XPM catalogue as an independent realization of the International Celestial Reference System, and to use it as a standard when comparing with other systems of coordinates.

The XPM-1.0 is the regular version of the XPM catalogue. In comparison with XPM the astrometric catalogue of about 280 millions stars covering entire sky from -90 to +90 degrees in declination and in the magnitude range 10^m