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beatrice bucciarelli slides put together by norbert zacharias n.
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report AC/CdC WG PowerPoint Presentation
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report AC/CdC WG

report AC/CdC WG

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report AC/CdC WG

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  1. Beatrice Bucciarelli (slides put together by Norbert Zacharias) report AC/CdC WG

  2. overview • efforts since last IAU with goals: • exploit scientific potential of these plates • make digitized images available to community • specific achievements summarized here

  3. Cordoba Zone • plates digitized with UMAX Astra1220P • low resolution, quick-and-raw • Calderon et al. 2004, Astroph.Sp.Sc. 290, 345 • positional accuracy ~ 1 arcsec (TBD) • images available to community • high resolution images of areas upon request

  4. San Fernando • Real Inst. y Observ. de la Armada en S.F. • completed with precision scanner of AC/CdC • Dec zones -3 ... -9 deg • digitized in 2 orientations: 90 deg rotated • images in FITS on CD-ROM • copies can be requested from ROA, Spain

  5. CCD imaging • new method / reduction • Fierro & Calderon (2003, Rev.Mex. 39,303) • use CCD camera for AC/CdC plates • test on plates of Cordoba Zone • astrometric errors 0.2 to 0.25 arcsec (in comparison to Tycho-2) • likely worse for fainter stars

  6. Toulouse • Lamareille et al. (2003, A&A 402, 395) • AGFA Snapscan 12365 for CdC plates • for stellar photometry, 600 dpi • use 100 standard stars/plate • accuracy = 0.2 to 0.4 mag • depending on location on plate

  7. PM2000 • Ducourant et al. (2006 A&A 448, 1235) • proper motions catalog for 2,670,974 stars • complete to V = 15.4 • 512 CdC plates Bordeaux zone • plates digitized at APM, Cambridge • + recent epoch Bordeaux CCD meridian circ. • errors: 1.5 to 6 mas/yr depend. on mag

  8. Sydney • Fresneau et al. (2003 AJ 125, 1519, 2005 AJ 130, 2701) • set of 650 CdC plates of Syndey Observ. • digitized at APM, Cambridge • combine with GSC 1.2 data -> proper motions • identify high PM stars ( > 15 mas/yr) • derive distances, different. rotation gal.plane up to 500 pc from Sun • investigate VO

  9. summary • no 1 um accuracy (60 mas) on CdC plates • 2-3 um is achievable, worse at faint mags • = 0.2 to 0.3 arcsec at epoch 1900 • + recent epoch observ. --> 2 – 5 mas/yr • --> 25 ... 60 km/s tangent.veloc. at 500 pc • CdC plates need to be salvaged • unique 100 yr old picture of the sky • best interest: join PDPP and WG AC/CdC • what accuracy can scanners give?