This web site provides data on numbered and multiopposition asteroids, including orbital elements, their uncertainty, proper elements, and so on. The following catalogs are updated every month. The last monthly update has been based upon the observational data released by the MPC, containing the observations performed until September 19, 2008. The orbits are always recomputed when and if new observations are available, with the OrbFit free software. Note that the current operational AstDyS system is using the Fortran 95 version of the software; thus the format of the observation files [astname].rwo has been changed and cannot be read with the Fortran 77 version of the sofware. The format of the orbital elements files has not been changed. How does it work? These important links are at the top and bottom of every page: Object list To browse the list of objects in the AstDyS database. Observatory list To browse the list of observing stations. Search To search for a specific object or for objects with particular characteristics. Orbital elements Catalogs of Orbital elements Proper elements Catalogs of proper elements Related sites Links to related WWW sites. Info Information page: about AstDys, frequently asked questions, MJD conversion tables and other infos. Help Help window. WHAT'S NEW: Orbital elements Orbital elements catalogs, not only for numbered but also for unnumbered multiopposition and single opposition asteroids (observed for at least three nights). To access statistics click the icon.