TAU researchers help discover smallest extra-solar planet yet

Discovery of CoRoT-Exo-7b brings astronomers closer to finding planets on which life could exist.

By JUDY SIEGEL-ITZKOVICH
cool planets 88 (photo credit: )
cool planets 88
(photo credit: )
A Tel Aviv University team participated in research that has discovered a planet outside our solar system. This search is being carried out with help from the CoRoT satellite launched by the French Space Agency. Tuesday's announcement of the discovery was made at a Paris conference organized by the satellite's scientific team. CoRoT is short for Convection, Rotation and planetary Transits. Dr. Shai Zucker of the geophysics and planetary sciences department, and Prof. Zvi Mazeh and his student Avi Shprorer from the astrophysics department helped discover a planet called CoRoT-Exo-7b, which has a radius 70 percent larger and a mass four times greater than that of Earth. It is the smallest of the 330 planets discovered so far outside the solar system and is 390 light-years away, left of Orion in dim Monoceros, the Unicorn. This discovery brings astronomers closer to discovering extra-solar planets on which life could exist, though this newly revealed planet cannot sustain life. It revolves around its star once every 20 hours and is very close to it. As a result, its surface temperature is very hot, over 1,000 degrees Celsius - too hot for life forms. The French satellite searches for events in which a planet revolves around a distant star, hiding part of it from us on Earth for a short time. Such an event, which recurs with every revolution, makes it possible for researchers to measure the planet's radius, and observations from our planet result in estimates of its mass. When it hides the star, the light that reaches us is weakened us by 0.03%. Only measurements by a satellite outside the atmosphere allows such sensitivity. Even though Israel did not help fund the satellite's construction and launch, the Israeli scientists were invited to analyze its observations because they have proven their abilities to do so in the past.