Based on observations obtained at the European Southern Observatory (ESO, La Silla, Chile), Calar Alto Observatory operated by the MPIA (DSAZ, Spain), Lowell Observatory (Flagstaff/AZ, USA), and Hoher List Observatory (Germany).

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Present address: Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, Arizona 85721, U.S.A.

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... Survey

The Digitized Sky Survey was produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166.

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... NED

The NASA/IPAC Extragalactic Database (NED) is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

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