AAS 203rd Meeting, January 2004
Session 4 Computation, Data Handling and Image Analysis
Poster, Monday, January 5, 2004, 9:20am-6:30pm, Grand Hall

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[4.02] CCD Flatfield Correction by Differential Stellar Photometry: Automated Methods

R. P. Boyle (Vatican Obs.), R. Janusz (U. College Ignatianum, Cracow), V. Laugalys (ITPA, Vilnius), A.G.D. Philip (Union College and ISO)

Calibrating CCD stellar fields to derive precise, one percent, photometry requires corresponding validity in the assumption of unit input sent through the telescope optical system for making the initial flat. Twilight or nighttime sky or even dome light might make the initial flat. Scattered light can compromise the applicability of the flat for quality photometry. Test exposures on a rich star field can provide data to reveal the error of the flat, and also may be used to correct the initial flat. We have developed automated methods for tuning the initial flat so as to confidently apply the corrected flat to other stellar fields having just single exposures in an observing run.


The author(s) of this abstract have provided an email address for comments about the abstract: rboyle@as.arizona.edu

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.