ACTIVITY OF THE WG TEAMS
- Densification of the celestial reference frame beyond Hipparcos and Tycho
- 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
- 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
- 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,
- 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.
Updated: 30 August 2017 - Home page: http://iau_wgnps.imcce.fr