report AC/CdC WG

1
report AC/CdC WG

• Beatrice Bucciarelli
• (slides put together by Norbert Zacharias)

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, AA 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 AA 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 -gt proper motions
• identify high PM stars ( gt 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. --gt 2 5 mas/yr
• --gt 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?