Stellar astrometry

• Densification of the celestial reference frame beyond Hipparcos and Tycho (www.usno.navy.mil/USNO/astrometry/optical-IR-prod/ucac and ad.usno.navy.mil/dens_wg).
• Densification of the optical reference frame in declination zone -3 to 30 deg.
• Reduction or re-reduction of photographic plates in order to get positions and proper motions before launching of new space missions(see for example www.aip.de/groups/plate_archive/plates_2009/plates2009_pauwels.pdf ).
• Proper motion of globular clusters, open clusters and young stars with the purpose to establish the possible connection between star formation and trajectories of molecular clouds across the galactic disk.
• Observation of relative proper motions and radial velocities in open clusters for dynamical studies.
• Extend the HIPPARCOS/Tycho catalogs to the fainter objects (V<15) present in very crowded fields.
• Observation of radiosource optical counterparts for connecting optical and radio reference frames.
• Astrometric observations for the determination of orbits and parallaxes for binaries needed for mass estimates.
• Determination of parallaxes for M-dwarfs in the solar neighborhood. Candidates could be selected from their high proper motions and/or from DENIS (and other) surveys.
• Observations of parallaxes of very faint stars (V > 15) are of great importance. In this case, the observations will keep their relevance until GAIA results will be available.
• Detection of very close double stars by speckle interferometry.
• Double stars at wider separations and large delta-m with no modern observations. The southern hemisphere has been neglected and is very poorly observed at all separations and magnitudes.
• Radial velocities of astrometrically well observed stars (e.g. Hipparcos stars)
• Photometry of clusters and variable stars.

Solar System Astrometry

• Astrometric observations on alert of potentially new Solar System Objects detected by Gaia through the Gaia Follow Up network for Solar System Objects Gaia-FUN-SSO . More details can also be accessed in the article Potential asteroid discoveries by the ESA Gaia mission. Results from follow-up observations

• Astrometry of natural satellites through the ESPaCE European project: the FP7-ESPaCE project operating from 2011 to 2015 aims at providing, thanks to a large international collaboration, new data and new accurate ephemerides of moons and spacecraft based on the exploitation of space and ground-based observations. Radio science, VLBI tracking, Laser ranging but also optical astrometry are involved. A specific work on CCD frames and digitized photographic plates is performed. Further information is accessible here. (ESPaCE stands for European Satellite Partnership for Computing Ephemerides)
• Astrometric observations of the natural planetary satellites for dynamical purpose (program implying several observatories coordinated by IMCCE and the IAU Working Group on Natural Satellites, http://www.imcce.fr/hosted_sites/iau_wgnps/iauwg.html)
• Astrometric observations of asteroids and Pluto for dynamical goals and in particular for mass determination and search for satellites of asteroids.
• Photometry for astrometry in the frame of international campaigns of observation of the mutual phenomena of several natural satellites (since 1974): a new campaign is organized in 2015 for the Jovian mutual events (see http://www.imcce.fr/phemu )- several campaigns have already been performed for the Saturnian and the Uranian systems.
• Observations of occultations of stars by solar system bodies (international network of observers)
• Special attention to the new NEOs. Searching for new TNOs.
• Definition and Observation of the Sun radius, comparison with Space measurements to know the origin of the apparent variations of this radius.