Planet Detection Capabilities of the Eddington Mission

Eddington is a space mission for extrasolar planet finding and for asteroseismic observations. It has been selected by ESA as an F2/F3 reserve mission with a potential implementation in 2008-13. Here we describe Eddington’s capabilities to detect extrasolar planets, with an emphasis on the detection of habitable planets. Simulations covering the instrumental capabilities of Eddington and the stellar distributions in potential target fields lead to predictions of about 10,000 planets of all sizes and temperatures, and a few tens of terrestrial planets that are potentially habitable. Implications of Eddington for future larger scale missions are briefly discussed. 1. The Eddington mission The Eddington mission is a space telescope designed for two primary goals: asteroseismic studies and extrasolar planet finding. Both goals will be achieved through the acquisition of high-precision wide-field photometry, with a temporal stability that is possible only from space. The basic design is an f/3 triplereflecting telescope with a 1.2m diameter aperture, 0.6m effective area, and a 3◦ diameter field of view imaged by a 20-CCD mosaic camera. The telescope will be launched into an orbit around the L2 Earth-Sun libration point, from which the entire sky is accessible for observations. The first 2 years of the mission will be dedicated primarily to asteroseismic studies, with pointings lasting up to two months to a variety of targets. The mission’s second part will be dedicated to planet finding by the transit method, where the telescope will survey a C. Aerts, E. Antonello, M. Badiali, C. Catala, J. Christensen-Dalsgaard, A. Gimenez, M. Grenon, A. Penny, H. Rauer, I.W. Roxburgh, J. Schneider, N.R. Waltham 1 2 Deeg, Horne, Favata & Eddington Science Team nu m be r of p la ne ts10 000