ESPRI: Astrometric planet search with PRIMA at the VLTI

A Quirrenbach,D Queloz,F Pepe,Espri Team ,R Geisler,J Setiawan,T Henning,N Elias,S Reffert,D Ségransan,R Launhardt

doi:10.1051/epjconf/20111607005

Abstract

The ESPRI consortium will conduct an astrometric survey for extrasolar planets, using the PRIMA facility at the Very Large Telescope Interferometer. Our scientific goals include determining orbital inclinations and masses for planets already known from radial-velocity surveys, searches for planets around nearby stars of all masses, and around young stars. The consortium has built the PRIMA differential delay lines, developed an astrometric operation and calibration plan, and will deliver astrometric data reduction software.

Highlights

Extrasolar planets have become the subject of many studies during the past one and a half decades
The ESPRI consortium will conduct an astrometric survey for extrasolar planets, using the PRIMA facility at the Very Large Telescope Interferometer
Astrometry offers an alternative approach to the detection and characterization of extrasolar planets, with better sensitivity to long-period orbits, and the capability to determine the mass of non-transiting planets

Summary

INTRODUCTION

Extrasolar planets have become the subject of many studies during the past one and a half decades. For non-transiting planets the product of their mass and the sine of the orbital inclination, m sin i, can be derived from radial-velocity measurements; the combination of data from both techniques yields the mass for transiting objects. Both techniques are strongly biased towards the detection of planets in short-period orbits. Ground-based astrometry is limited by the Earth’s atmosphere, but measurements with a precision of tens of microarcseconds are possible relative to reference stars located nearby on the sky The precision of such narrow-angle data improves with the aperture diameter, making interferometry with baselines of ∼100 . We describe the preparations for an astrometric planet survey with the European Southern Observatory’s Very Large Telescope Interferometer (VLTI), by the ESPRI consortium

INTERFEROMETRIC ASTROMETRY

PRIMA AT THE VLTI

ASTROMETRIC PLANET DETECTION

GOALS OF ESPRI

REFERENCE STARS AND PREPARATORY OBSERVATIONS