was in active operation from 2009 through 2013, with the first main results announced on January 4, 2010. As expected, the initial discoveries were all short-period planets. As the mission continued, additional longer-period candidates were found. , Kepler has discovered 5,011 exoplanet candidates and 2,662 confirmed exoplanets. As of August 2022, 2,056 exoplanet candidates remain to be confirmed and 2,711 are now confirmed exoplanets. 2009 NASA held a press conference to discuss early science results of the Kepler mission on August 6, 2009. At this press conference, it was revealed that Kepler had confirmed the existence of the previously known transiting exoplanet HAT-P-7b, and was functioning well enough to discover Earth-size planets. Because Kepler's detection of planets depends on seeing very small changes in brightness, stars that vary in brightness by themselves (variable stars) are not useful in this search. From the first few months of data, Kepler scientists determined that about 7,500 stars from the initial target list are such variable stars. These were dropped from the target list, and replaced by new candidates. On November 4, 2009, the Kepler project publicly released the light curves of the dropped stars. The first new planet candidate observed by Kepler was originally marked as a false positive because of uncertainties in the mass of its parent star. However, it was confirmed ten years later and is now designated Kepler-1658b. The first six weeks of data revealed five previously unknown planets, all very close to their stars. Among the notable results are one of the least dense planets yet found, two low-mass white dwarfs that were initially reported as being members of a new class of stellar objects, and Kepler-16b, a well-characterized planet orbiting a binary star. 2010 On June 15, 2010, the Kepler mission released data on all but 400 of the ~156,000 planetary target stars to the public. 706 targets from this first data set have viable exoplanet candidates, with sizes ranging from as small as Earth to larger than Jupiter. The identity and characteristics of 306 of the 706 targets were given. The released targets included five candidate multi-planet systems, including six extra exoplanet candidates. Only 33.5 days of data were available for most of the candidates. NASA also announced data for another 400 candidates were being withheld to allow members of the Kepler team to perform follow-up observations. The data for these candidates was published February 2, 2011.