 Ground-based telescopes in California, Hawaii, the Canary Islands, Arizona, and Texas, as well as the Spitzer Space Telescope, were used to conduct these follow-up observations and verify Kepler-11b's existence. In particular, the detection of an orbital resonance effect between Kepler-11b and Kepler-11c confirmed the find. Kepler-11b's discovery was announced to the public on February 2, 2011. It is part of the first system discovered with more than three transiting planets, and is also part of the most compact and flat system yet discovered. Kepler-11's planetary system is the second known system to have multiple transiting planets, surpassing the three confirmed planets (two transiting) orbiting the star Kepler-9.
