The Institut de Mécanique Céléste et de Calcul des Ephémérides (IMCCE) was created by decree of June 2, 1998 and replaced the Service des calculs et de mécanique céleste of the Bureau des Longitudes. This decree confers to the IMCCE a structure of institute (according to the article 33 of the universities) within the Observatoire de Paris, but it conserves the link between the IMCCE and the Bureau des Longitudes. In addition to a research mission, it has a service assignment: the development of the national ephemeris. The IMCCE is also a Unité Mixte de Recherche du CNRS, the UMR 8028.


The IMCCE is composed of engineers or technicians and researchers and teacher-researchers. These personnel depend on the Ministère de l'Education Nationale et de la Recherche, or of the CNRS. 35 People are on permanent positions and by taking account of students, trainees and foreign guests; the staff of the IMCCE is about 50 people.


The IMCCE has two main activities: a mission of research in the celestial mechanics fields under its mathematical and dynamic aspects, in astrometry and planetology and a mission of service devoted to the ephemeris development.


research topics are carried out within the framework of four research teams works. The Dynamic Systems and Astronomy team (ASD), the Asteroids, Comets, Meteors and Ephemeris team (ACME), and (PEGASE) work on different topics related to dynamics and the solar system. These teams collaborate narrowly on the transverse topics.

The IMCCE research tasks led to many publications in various periodicals and scientific newspapers. The complete list of these articles is ici. A more complete description of the structure and activities of the Institut de mécanique céléste et de calcul des éphémérides (IMCCE) is given in the various activity reports.


The IMCCE elaborate and diffuse several types of ephemerides:

For more details about these publications, click here

Besides the edition of these publications, the Institut de mécanique céleste et de calcul des éphémérides is a French official service which carries out a specific astronomical calculations for various public or institutional users. These calculations are carried out on the request of different administrative organizations such as police, courts, insurance companies, architects, film-makers or for the account of scientific organizations such as the astronomical observatories or the space agencies.

An interactive ephemeris Internet server is available for astronomers and public who wish to obtain the solar system star position and their physical parameters.

General public, amateur astronomers and associations also request the Institute which has developed a public directory


Beyond the solar system objects' ephemerdes computations and publications tasks, the IMCCE has for a long time a strong implication in space research.

During years, the IMCCE intervened in the preparation of scientific missions such as Hipparcos, ISO, and intervenes in Rosetta or Gaia. It also provided a scientific support throughout the ISO and BeppoSAX missions. The IMCCE space research works evolved with the increasing needs of the public and private space and consortium agencies. Post-doctoral stays and theses in joint guardianship are financed within this framework.

Its role in the fields of the space probes orbitography and its expertise in the implementation of the reference frames and the solar system objects' theories of movements as in the computation of ephemeris make IMCCE a partner in the preparation of the solar system exploration of the European space missions.

For more details on these space activities, click here.


The Institut de mécanique céleste et de calcul des éphémérides has also an activity of teaching and training:

  • researchers of the establishment offer courses of Master de l'observatoire de Paris and in several universities (Paris 6, Paris 7, Paris XI and Lille 1), on related subjects to the research topics of the Institut (celestial mechanics, astrometry, mathematics).
  • The establishment receives students in engineering who come to carry out training courses from 3 to 6 months, supervised by researchers of the IMCCE.
  • des seminars and conferences addressed to various public are also proposed by the IMCCE.
Caution : This Website was created with the Ministère de l'Education Nationale, the CNRS and the CNES support. Any use of the data published on this website requires the IMCCE agreement..