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Register a new userThe Optical Gravitational Lensing Experiment. High Proper Motion Stars in the OGLE-III Data for Magellanic Clouds Fields
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Rados{\\l}aw Poleski
Publication date
2011
fields
Physics
and research's language is
English
Authors
R. Poleski
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We present the results of a search for High Proper Motion (HPM) stars, i.e. the ones with mu > 100 mas/yr, in the direction to the Magellanic Clouds. This sky area was not examined in detail as the high stellar density hampers efforts in performing high-quality astrometry. Altogether 549 HPM stars were found with median uncertainties of proper motions per coordinate equal to 0.5 mas/yr. The fastest HPM star has the proper motion of 722.19 +/- 0.74 mas/yr. For the majority of objects (70%) parallaxes were also measured. The highest value found is pi = 91.3 +/-1.6 mas. The parallaxes were used to estimate absolute magnitudes which enriched with color information show that 21 of HPM stars are white dwarfs. Other 23 candidate white dwarfs were selected of HPM stars with no measurable parallaxes using color-magnitude diagram. The search for common proper motion binaries revealed 27 such pairs in the catalog. The completeness of the catalog is estimated to be > 80% and it is slightly higher than for previous catalogs in the direction to the Magellanic Clouds.
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We present a Catalog of high proper motion (HPM) stars detected in the foreground of central parts of the Magellanic Clouds. The Catalog contains 2161 objects in the 4.5 square degree area towards the LMC, and 892 HPM stars in the 2.4 square degree area towards the SMC. The Catalog is based on observations collected during four years of the OGLE-II microlensing survey. The Difference Image Analysis (DIA) of the images provided candidate HPM stars with proper motion as small as 4 mas/yr. These appeared as pseudo-variables, and were all measured astrometrically on all CCD images, providing typically about 400 data points per star. The reference frame was defined by the majority of background stars, most of them members of the Magellanic Clouds. The reflex motion due to solar velocity with respect to the local standards of rest is clearly seen. The largest proper motion in our sample is 363 mas/yr. Parallaxes were measured with errors smaller than 20% for several stars.
We present OGLE-III Photometric Maps of the Galactic disk fields observed during the OGLE-III campaigns for low luminosity transiting objects that led to the discovery of the first transiting exoplanets. The maps contain precise, calibrated VI photometry of about 9 million stars from 21 OGLE-III fields in the Galactic disk observed in the years 2002-2009 and covering more than 7 square degrees in the sky. Precise astrometry of these objects is also provided. We discuss quality of the data and present a few color-magnitude diagrams of the observed fields. All photometric data are available to the astronomical community from the OGLE Internet archive.
We present OGLE-III Photometric Maps of the Galactic bulge fields observed during the third phase of the OGLE project. This paper describes the last, concluding set of maps based on OGLE-III data. The maps contain precise, calibrated VI photometry of about 340 million stars from 267 fields in the Galactic bulge observed during entire OGLE-III phase (2002-2009), covering about 92 square degrees in the sky. Precise astrometry of these objects is also provided. We briefly discuss the photometry procedures and the quality of the data. We also present sample data and color-magnitude diagrams of the observed fields. All photometric data are available to the astronomical community from the OGLE Internet archive.
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