The TEP network — a search for transits of extrasolar planets: Observations of CM draconis in 1994

Abstract

Abstract The TEP (Transits of Extrasolar Planets) network undertakes the only current search for terrestrial sized planets around MS-Stars. TEP was formed in 1994 to observe transits of extrasolar planets around eclipsing binaries. The current search is concentrated on CM Draconis, which is the lowest mass eclipsing binary known (dM4.5/dM4.5). It is also relatively close (17 pc), has a period of 1.26 d, and its orbital plane is nearly within our line sight (i = 89.8°). These conditions give a unique opportunity to determine the existence, or non-existence, of planets around this binary by photometric means with a high degree of certainty. Planetary orbits, if present, will be within the orbital plane of the binary components, and - due to the small size of the components - create photometrically detectable transits. The transit of a Jupitersized planet will cause a brightness drop of 8%, an Earth-sized planet one 0.08%, which is detectable with subnoise detection algorithms. The low mass and temperature o...