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Published online by Cambridge University Press:  18 November 2008

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Various experiments have definitely demonstrated that one-micron accuracy (0.″06) on the definition of stellar images on CdC plates cannot be claimed, as it was speculated back in 1999. More realistically, a 2-3 micron accuracy is achievable, getting worse toward the survey magnitude limit, with an average magnitude error of 0.3. The level of astrometric accuracy corresponds to a 0.″2 - 0.″3 error in position at Epoch 1900, which, once used as first Epoch for proper motion determination in combination with modern epoch observations, can produce errors at the level of 2-5 mas/yr, thereby allowing to detect stellar motions larger than 0.″01/yr, which at a distance of 500 pc from the Sun correspond to ~25-60 km/s tangential velocity. Therefore, the AC/CdC heritage collection can be regarded as a highly valuable first-epoch material, e.g., for the realization of a Tycho-2 extension to fainter magnitudes (~15 photographic), especially in selected areas where radial velocity data are available, for the exploration of stellar kinematics beyond our solar neighborhood.

Contributed Papers
Copyright © International Astronomical Union 2008


Bustos Fierro, I. H., & Calderón, J. H. 2003, RMAA 39, 303Google Scholar
Calderón, J. H., Bustos Fierro, I. H., Melia, R., Willimoës, C., & Giuppone, C. 2004, ApSpSci 290, 345Google Scholar
Ducourant, C., Le Campion, J. F., Rapaport, M., Camargo, J. I. B., Soubiran, C., Périe, J. P., Teixeira, R., Daigne, G., Triaud, A., Réquième, Y., Fresneau, A., & Colin, J. 2006, A&A 448, 1235Google Scholar
Fresneau, A., Vaughan, A. E., & Argyle, R. W. 2003, AJ 125, 1519Google Scholar
Fresneau, A., Vaughan, A. E., & Argyle, R. W. 2005, AJ 130, 2701Google Scholar
Lamareille, F., Thiévin, J., Fournis, B., Grimault, P., Broquet, L., & Davoust, E. 2003, A&A 402, 395Google Scholar
Rapaport, M., Ducourant, C., Le Campion, J. F., Fresneau, A., Argyle, R. W., Soubiran, C., Teixeira, R., Camargo, J. I. B., Colin, J., Daigne, G., Périe, J. P., & Réquième, Y. 2006, A&A 449, 435Google Scholar