The star positions derive from the USNO-A2.0 and PPM catalogs. The asteroid positions are supplied from the Lowell Observatory asteroid catalog and from orbits published in the Minor Planet Electronic Circulars . Cookies Cookies are used to store default values for the user.
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If you choose to suppress them for this application, you will have to supply the listed parameters each time you visit this service. Date Limits and Equinox Users should not select dates outside the range 1890 to 2020. Asteroid positions are calculated using full planetary perturbations. All positions are plotted at equinox J2000.0. A 5-minute time limit has been placed on this service in order to be fair to other server requests.