Conceptual Design Review PRIMA Astrometry Operations and Software

Introduction In less than 10 years after the first detection of a planet orbiting another star, more than 100 giant extra-solar planets have been discovered. This avalanche of results has opened a very exciting field of research: exploration of the characteristics of other planetary systems. The discoveries of the past few years have stimulated new planetary formation models leading to a new picture of planet formation. So far, all extra-solar planets found around stars in the vicinity of the Sun have been detected by radial-velocity measurements. Large surveys are conducted in both hemispheres with about 3000 G, K and early M stars being monitored regularly. While these surveys are very successful, their intrinsic biases imply some limitations both on the detection sensitivity and the data interpretation. In particular, this method is restricted to certain types of stars and leaves the inclination angle of the orbit sin i undetermined, thus providing only a lower limit to the mass of the planets. The development of state-of-the-art optical long-baseline interferometric instruments like the Very Large Telescope Interferometer on Cerro Paranal opens new perspectives in this research area. The European Southern Observatory (ESO) is currently acquiring the hardware for PRIMA, a facility that will enable astrometric observations with the Very Large Telescope Interferometer (VLTI). The PRIMA facility holds the promise to carry out an exciting program on the astrophysics of extra-solar planets through precise astrometry, which is a very complementary technique to the radial-velocity method. It has a different detection bias, favoring planets in large orbits versus the short-period orbits preferentially detected by the radial-velocity technique. Moreover, astrometry measures two components (right ascension and declination) of the stellar reflex motion versus the single radial component that is observable spectroscopically. However, to play a significant role, an astrometric accuracy of order 10 µarcsec is needed, which is beyond the performance of current instrumentation (including HST). A consortium has formed that build the required hardware and develops the required software, to turn the PRIMA astrometry facility in a successful science instrument which delivers astrometric information at unprecedented accuracy. This three day workshop focuses on a Conceptual Design Review of the consortium activities related to the PRIMA astrometric operations and software. Additional information is available at:

§       http://obswww.unige.ch/Instruments/PRIMA/

§       http://www.eso.org/projects/vlti/instru/prima/index_prima.html Date: Start on Wednesday 29 September 2004, at 10:00 End on Friday 01 October 2004, at 16:00 Invited participants and attendants: Everybody who has actively contributed to any of the document to be discussed Management team of PRIMA PSP consortium (key personnel)