IV. An improved geometric-distortion correction for the blue prime-focus camera at the LBT
Dipartimento di Astronomia, Università di Padova, Vicolo
dell'Osservatorio 3, 35122 Padova, Italy
2 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA e-mail: [bellini;bedin]@stsci.edu
Accepted: 16 April 2010
High precision astrometry requires an accurate geometric-distortion solution. In this work, we present an average correction for the blue camera of the Large Binocular Telescope which enables a relative astrometric precision of ~15 mas for the and VBessel broad-band filters. The result of this effort is used in two companion papers: the first to measure the absolute proper motion of the open cluster M 67 with respect to the background galaxies; the second to decontaminate the color-magnitude of M 67 from field objects, enabling the study of the end of its white dwarf cooling sequence. Many other applications might find this distortion correction useful.
Key words: instrumentation: detectors / astrometry
Based on data acquired using the Large Binocular Telescope (LBT) at Mt. Graham, Arizona, under the Commissioning of the Large Binocular Blue Camera. The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia.
© ESO, 2010