The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark III system, a set of wide-field drift-scan CCD cameras which monitor the celestial equator down to thirteenth magnitude in several passbands. We explain the methods by which images are gathered, processed, and reduced into lists of stellar positions and magnitudes. Over the period October, 1996, to November, 1998, we compiled a large database of photometric measurements. One of our results is the tenxcat catalog, which contains measurements on the standard Johnson-Cousins system for 367,241 stars; it contains links to the light curves of these stars as well. (Refer to PDF file for exact formulas).

Publication Date



This is the pre-print of a paper published by the Astronomical Society of the Pacific. The final, published version is available here: https://doi.org/10.1086/316527 under the title "TASS Mark III Photometric Survey of the Celestial Equator"

© 2000 Astronomical Society of the Pacific

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Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. AMG acknowledges support from a NASA GSRP grant. Also archived in: arXiv:astro-ph/9910267 v1 14 Oct 1999

Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus