DEPARTMENT 2 : ASTROMETRY AND DYNAMICS OF CELESTIAL BODIES

Section 4 : ASTROMETRY AND DYNAMICS OF OBJECTS IN OUR SOLAR SYSTEM

The Scientific activities of this section are divided over 3 projects :

• Project RUSTICCA

  The project RUSTICCA, which stands for "Revalorising the Uccle Schmidt Telescope by Installing a Ccd CAmera", was initiated in 1996, and consists of a modernisation of the Uccle Schmidt Telescope, and the installation of a CCD camera. The main goal of this camera was to perpetuate the long-lasting tradition of excellent astrometric observations of asteroids from Uccle. In the period 1996-2010, this project has produced some 20 000 astrometric observations of asteroids and more than 100 asteroid discoveries. With the advent of massive surveys elsewhere in the world, potential discoveries of asteroids are getting exhausted and consequently this observing programme is now well over its apogee.

  The same camera and telescope have also been used for other kinds of observations: photometry of cataclysmic variables (discontinued since the people involved in this research left the Observatory), photometric observations of mutual phenomena of the Galilean satellites of Jupiter, photometric observations of asteroids and their satellite involved in mutual phenomena, and observations of stellar occultations by asteroids. Also photometry of asteroids for rotational parameters are envisaged. All these observations are expected to become more important when astrometry of asteroids will loose its interest with

  
  
• Project GAIA

  The Royal Observatory is involved in the software development of the data reduction of the astrometric satellite Gaia (see http://www.rssd.esa.int/index.php?project=GAIA&page=index). Our section has been assigned the role (and the leadership) of DU454, the developing unit responsible for the astrometric reduction (transformation of pixel coordinates in the focal plane to celestial coordinates) of Solar System Objects.
  http://www.astro.oma.be/gaia

  
  
• Project DIGITISATION

  In the course of the 20th century the department has acquired a set of about 25000 photographic plates of the night sky, representing an unvaluable historic scientific data set. These are very difficult to exploit scientifically, because of the risk posed by the manipulation of the plates, the difficult access (stored in cabinets in a cellar), and the non-evident way to transform the analogue image on the emulsion to something that can be investigated scientifically in an efficient way.

  Therefore, the Royal Observatory has built Damian, a high-precision digitiser, capable to digitise photographic plates up to 35x35 cm with the best possible accuracy, both positional (100 nm) and photometrical. After an upgrade, a photographic plate will be digitised in a few minutes.

  In parallel a climatised archive room has been installed, capable of hosting not only our own collection of photographic plates, but also photographic plates from other Observatories who have lost the know-how of handling such plates, who have no interest any more in their own collections, who have no money to properly store them or to make them available, or who are in lack of space to store them. This is the project UDAPAC (Uccle Direct Astronomical Plate Archive Centre). The first achievement will be the move of the ESO plate collection from Garching to Uccle (2011 or 2012).

  
  
• OTHER TASK

  The section is also responsible for the production of the Yearbook, giving ephemerides of celestial objects and celestial phenomena, and their visibility in Belgium.

  
  

Scientific staff :

• Pauwels Thierry (Head of Section)
• De Cat Peter

Section 5 : ASTROMETRY AND DYNAMICS OF DOUBLE AND MULTIPLE STAR SYSTEMS

Our research interest lies in the domain of stellar physics, in particular we study the physical processes occuring in the stellar atmospheres of various classes of early- to mid-type main-sequence stars. Concerning the B/Be-type stars, we focus on stellar rotation and pulsation as well as the influence of an environment with varying metallicity. Concerning the A/F-type stars, we focus on pulsation, chemical composition and multiplicity. All these processes are relevant for the study of stellar evolution. Another research topic is double and multiple stars, ranging from the (wide) visual double stars via the (closer) speckle binaries to the very close pairs, including also spectroscopic and photometric binary systems. Indeed, the vast majority of all stars is a member of such systems. In the solar neighbourhood, at least 2 out of 3 stars are belonging to a binary or multiple star system.

The research activities of this section are divided over 5 projects :

• Double and multiple stars
• Stellar characterization
• Asteroseismology
• GAIA
• Instrumentation:
• Humain Observatory for Astrophysics of Coeval Stars
• Hermes

Scientific staff :

• Lampens Patricia (Head of Department)
• Frémat Yves
• Jean-Pierre De Cuyper

Supporting staff :

• Thienpont Emmanuel (2010 - 2011)
• Georges De Decker
• Eric Van Hemelryck

Former staff & visitors :

• Torres Kelly (Supplementary researcher : 2009 - 2011)
• Wright Duncan (Action 1 researcher : 2008 - 2010)
• Hekker Saskia (Action 1 researcher : 2008 - 2009)
• Strigachev Anton (Bulgarian Academy of Sciences)