The XPM Catalog of positions and proper motions of stars
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The XPM Catalogue. Absolute proper motions of 280 million stars
Fedorov P., Myznikov A., Akhmetov V.,
< MNRAS, 393, 133, (2009)>
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Keywords: astrometry; reference systems; catalogues; proper motions;
  Galaxy: kinematics and dynamics


Description:
    We combined the data from 2MASS and USNO-A2.0 catalogues in order to derive
the absolute proper motions of about 314 million stars distributed all over the sky
without gaps in the magnitude range 10m < V <20m . The proper motions were derived
from 2MASS Point Sources and USNO-A2.0 catalogues positions, with the mean epoch
difference of about 45 years for the northern hemisphere, and about 17 years
for the southern one. Most of the systematic zonal errors inherent in the USNO-A2.0
catalogue were eliminated before calculation of the proper motions. The zero-point
of the absolute proper-motion frame (the “absolute calibration”) was specified
with the use of about 1.1 million of extended sources from 2MASS and  USNO-A2.0.
In fields covering the zone of avoidance or those that contain fewer than 25 galaxies,
quasi-absolute calibration was performed.   The mean formal error of absolute calibration
is less than 1 mas/yr. The generated Catalogue contains the ICRS positions of stars
for the 2000.0 epoch, original absolute proper motions, as well as F, J, V, N magnitudes
from GSC2.3; B, R magnitudes from USNO-A2.0 and J, H, Ks magnitudes from 2MASS.

File Summary:
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 FileName   Records Explanations
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ReadMe              This file
dat/*       360     xpm***.txt files organized by declination zones of 30' and 
		     sort by right ascension. 
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See also:
I/252  : The USNO-A2.0 Catalogue (Monet+ 1998)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/305  : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006) 

Description of file: *.txt
The files are ASCII, free format with tab separator columns
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Format  Units    Label   	Explanations
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  F.6   deg      RA      	Right Ascension (ICRS, epoch 2000.0)
  F.6   deg      DEC     	Declination (ICRS, epoch 2000.0)
  F.2   mas/yr	 MuRAp*  	Proper Motion in RA*cos(DEC) (mas/yr)
  F.2   mas/yr   MuDEp*  	Proper Motion in DEC (mas/yr)
  F.2   mas/yr	 MuRAx** 	Proper Motion in RA*cos(DEC) (mas/yr)
  F.2   mas/yr   MuDEx** 	Proper Motion in DEC (mas/yr)
  F.3   mag      Fmag    	Magnitude from GSC2.3
  F.3   mag      Jmag    	Magnitude from GSC2.3
  F.3   mag      Vmag    	Magnitude from GSC2.3
  F.3   mag      Nmag    	Magnitude from GSC2.3
  F.3   mag      j_m     	J magnitude from 2MASS
  F.3   mag      er_jmag 	Standard error on J magnitude
  F.3   mag      h_m     	H magnitude from 2MASS
  F.3   mag      er_hmag 	Standard error on H magnitude
  F.3   mag      k_m     	Ks magnitude from 2MASS
  F.3   mag      er_kmag 	Standard error on Ks magnitude
  I10   ---      pts_key 	Unique source identifier in 2MASS
  I3    mag*10   Bmag_ua 	Magnitude from blue plate USNO-A2.0
  I3    mag*10   Rmag_ua 	Magnitude from red plate USNO-A2.0
  I3    ---      field   	USNO-A2.0 field number 
  F.6   year     dT      	Difference of epochs between 2MASS and USNO-A2.0 
  bit   ---     “good_gal” 	if flag =0, the proper motion was derived using a
                 		quasi-absolute calibration. 
  bit   ---     “gal_star” 	if flag =1, the extended source was used for absolute
                 		calibration
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Note (1):
•	*-   the zero-point of the proper motion was derived using the PSC coordinates of extended sources
•	**-  the zero-point of the proper motion was derived using the XSC coordinates of extended sources
 
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In case of any problems or questions, please contact by e-mail P.  N. Fedorov (pnfedorov@gmail.com)
or V. S. Akhmetov (akhmetov@astron.kharkov.ua).
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 References:
  1. P. N. Fedorov, A. A. Myznikov and V. S. Akhmetov 
  “The XPM Catalogue: absolute proper motions of 280 million stars ”
   Mon. Not. R. Astron. Soc. 393, 133–138 (2009) 
  
  2. P. N. Fedorov, V. S. Akhmetov, V. V. Bobylev and A. T. Bajkova 
 “ An investigation of the absolute proper motions of the XPM catalogue”
  Mon. Not. R. Astron. Soc. 406, 1734–1744 (2010)
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