This web site provides data on numbered and multiopposition asteroids, including orbital elements, their uncertainty, proper elements, ephemerides with uncertainty, and more.

The orbits and other information, as posted on the web page of each individual object, is periodically recomputed if new observations are available, with the OrbFit free software.

The following catalogs are updated every month, or anyway whenever the MPC releases a full update of the dataset: osculating orbital elements, analytical proper elements for Main Belt asteroids, residuals and quality control after the orbital fit. Other catalogs, such as synthetic proper elements, are updated periodically. The last monthly update has been based upon the observations performed until Sep 13, 2024.

What's new?

• The visualizer for proper elements has been updated in such a way that it can also handle proper elements computed in differently defined spaces, such as for Trojans, with proper a replaced by a + Delta a, where Delta a is the amplitude of libration in a, for the L5 swarm, and a - Delta a for the L4 swarm. For secular resonant g+g5-2g6 proper elements we replace e with Delta e + 0.7, where Delta e is the amplitude of libration in eccentricity.
• New feature: we are now providing improved proper elements for the region with proper between 2.5 and 2.7 au, proper sinI less than 0.3. This includes non-resonant synthetic proper elements computed over a longer timespan of 10 My and, for the same region, secular resonant proper elements specifically adapted to the most important nonlinear secular resonance g+g5-2g6. The resonant proper elements belong to a different space, and are not to be compared to the non-resonant ones. This region includes a newly determined, very large family of (5) Astraea.
• In the proper elements section we provide in a single catalog synthetic proper elements for numbered and multiopposition Main Belt asteroids and Hungarias, as well as for high I,e and unusual asteroids. We also provide lists of members of asteroid families, according to our most recent classification (updated June 2015).
• In the proper elements pages of individual asteroids we added auxiliary tables containing information on family membership and resonance status.

How does it work?

These important buttons and links are at the top and bottom of every page:

Objects

To browse the list of objects in the AstDyS database.

Observatories

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 & Credits

Information page: about AstDys, frequently asked questions, MJD conversion tables and other infos.

[Help]

Help window.

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This is the Tools icon (on the right in the top banner). Clicking repeatedly on it shows the following tools: Go to asteroid, Current date-time, MJD-calendar conversor and, finally, color and font-size selectors. When all the tools are displayed the icon changes to  ▼ . Clicking on  ▼  hides the tools and sets the icon again to  ▲ .

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Expands the main content area, hiding the banners and menus, to increase the available on-screen surface for data browsing. The same icon lets you restore the initial layout.

Contact »

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