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VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010. Proper motion accuracy of WFPDB stars. Yavor Chapanov 1 , Jan Vondrák 2 , Cyril Ron 3 , Vojtéch Štefka 2. 1 – Central Laboratory for Geodesy, Bulgarian Academy of Sciences
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VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 Proper motion accuracy of WFPDB stars Yavor Chapanov1, Jan Vondrák2, Cyril Ron3, Vojtéch Štefka2 1 – Central Laboratory for Geodesy, Bulgarian Academy of Sciences 2 – Astronomical Institute, Academy of Sciences of Czech Republic
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 DATA SELECTION PLATE SCALE <100"/mm SCAN RESOLUTION 2400dpi PLATE CENTER AND ORIENTATION IMPROVED DISTORTION MODEL ACCURACY: 0”.5 – the best case, 1” – raw plate center, 5” – scan resolution 300dpi
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 DATA SOURCE Catalogues of Wide-Field Plates • RA: 11 59 31.80, DEC: +47 45 55.4, radius: 5 deg – 2000 plates • 2. RA: 01 02 54.26, DEC: +41 20 42.6, box size: 5 deg – 700 plates • 3. RA: 11 59 31.80, DEC: -35 18 30.7, box size: 3 deg – 150 plates
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 ERROR MODEL – NORMAL DISTRIBUTION Normally distributed pseudo random numbers
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 TIPICAL ASTROMETRIC ERRORS According daily residuals of latritude observations at observatory Plana for the period 1987.5-1997.0
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 A MODEL OF TIPICAL ASTROMETRIC ERRORS 10000 Normally distributed numbers N (0, 0.1) Replaced by: 1%evenly distributed numbers from intervals (0.8, 0.4], [0.4, 0.8); 6%evenly distributed numbers from intervals(0.4, 0.1], [0.1, 0.4); 6%evenly distributed numbers from intervals(0.06, 0.06). Resulting s=0.14
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 ERROR MODEL – I (the best case) Standard 0.5 arcsec
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 ERROR MODEL – II Standard 1.0 arcsec
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 ERROR MODEL – III (the worst case) Standard 5 arcsec
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 RESULTS FROM 0.5” SERIES PM: 0.001”/a 0.01”/a 0,05”/a Estimates: 1. 0.00084 0.0098 0.0498 0.00059 0.0006 0.0006 2. 0.0013 0.0121 0.0521 0.0011 0.0011 0.0011 3. 0.0019 0.0119 0.0519 0.0023 0.0025 0.0025
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 RESULTS FROM 1” SERIES PM: 0.001”/a 0.01”/a 0,05”/a Estimates: 1. - 0.0092 0.0492 - 0.0011 0.0011 2. -0.00260.0186 - 0.00170.0022 RESULTS FROM 5” SERIES PM: 0.001”/a 0.01”/a 0,05”/a Estimates: 1. - 0.0074 0.0484 - 0.0049 0.0059
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 CONCLUSIONS • The WFPDB provide significant number of plates, containing a given star. The plates numbers vary from hundreds to several thousands and they cover century time span. It is possible to estimate the star proper motion with enough accuracy by means of the corrected plates for image center and distortion with 100”/mm scale and scan resolution 2400dpi. • It is possible to use the raw star images for estimation of the great proper motions, if the number of plates is more than 1000.
VII BSAC "ASTROINFORMATICS" – Chepelare, 1-4 June 2010 THANK YOU FOR ATTENTION