When I first reviewed the Planet Hunters Web site in January 2011, the project was in its infancy. The site and its navigation had some bugs to work out. But it had a compelling yet seemingly quixotic premise: That a group of volunteers, peering in Web browsers at graphs of stars' brightness based on public data from NASA's Kepler planet-hunting telescope, might be able to discover planets that Kepler's own search algorithms may have missed.
Two years later, that concept has been borne out beyond any skeptic's wildest imaginings. In September 2011, Planet Hunters announced its first two planet candidates, and soon after announced several more. The project's first confirmed discovery?a planet circling a binary star in a quadruple star system?came in fifth on CNN's list of the top 10 science stories of 2012.
In January 2013, the project announced a second confirmed planet?a Jupiter-sized world orbiting in the so-called habitable zone of a sunlike star?as well as 42 new planetary candidates, including 15 in their respective stars' habitable zones. These worlds?ranging in size from about 2.5 Earth radii up to slightly larger than Jupiter?are too large to support life as we know it, presumably being gas giants, they may well have large moons.
Planet Hunters volunteer Kian Jek was recently awarded the Chambliss Amateur Achievement Award, the American Astronomical Society's most prestigious award given annually to an amateur astronomer, for his work on behalf of the project. Kian, one of the two hunters credited with Planet Hunters' initial confirmed discovery, is one of a small cadre of skilled volunteers that have supported the Planet Hunters science team?who, although professionals, also volunteer their time to work on this project? by vetting and cataloguing potential planetary candidates, modeling stellar and planetary systems, keeping tabs on exotic variable stars such as ?heartbeat binaries? and dwarf novae, as well as tracking unlisted eclipsing binary systems in which a pair of stars orbit each other in our line of sight, each eclipsing the other in turn.
PC Planet Hunting
I've participated in a number of ?citizen science? online astronomy projects over the years, but none ?has sparked my imagination like Planet Hunters, which lets anyone with a computer and an Internet connection take part in one of modern science?s great quests: the search for planets orbiting other stars. On the Planet Hunters site, you can look for signs of these so-called exoplanets in public data from NASA's Kepler mission. If you're among the first to report a new planet, you get credit for the find and in some cases can have your name appear as a co-author on the discovery paper.
Planet Hunters is a collaboration between Yale University and the Zooniverse, a Web hub that hosts a number of citizen science projects. It got started with astronomy projects, the first being Galaxy Zoo, in which the public was enlisted to classify galaxies in images from the Sloan Digital Sky Survey; it's since added others such as Moon Zoo and Solar StormWatch. Nearly half of the 14 Zooniverse projects are astronomy related; of the others, one of them, Cell Slider focuses on identifying cells for cancer research; others are related to tracking wildlife, climate science, and studying the ancient Greeks. ?Although Planet Hunters isn't officially connected to the Kepler mission, there are close ties and cooperation between the two.
150,000 Points of Light
Kepler, a space telescope, was launched in March 2009, tasked with ??exploring the structure and diversity of planetary systems?.? (by discovering them), looking in particular for Earth-sized planets, and worlds in a star's habitable zone. After Kepler completed its basic mission in 2012, the mission was extended for another 3 years.
Kepler uses the ?transit method? for planet hunting, searching for tiny dips in a star?s brightness caused by the passage (transit) of a planet in front of the star. Kepler repeatedly (every 29 minutes) images the same star field near the constellation Cygnus showing more than 150,000 stars, using a photometer to precisely measure each star's brightness. These readings generate light curves?plots showing variations in a star's luminosity over time. A transit shows as a string of data points descending below the star's light curve. Kepler uses search algorithms to find transits in its data?so far it's credited with more than 100 exoplanet discoveries, and has published a list of more than 2,700 planet candidates.
But Kepler monitors a huge variety of stars: some of constant brightness, others that flicker erratically or pulsate like clockwork. Eclipsing binaries?two stars that orbit each other and periodically eclipse one another?often show transits similar to those from planets. Although Kepler's planet search algorithms are very good at detecting prospective planets, they don?t catch everything, and the human eye has been shown to be better at detecting anomalies in some pattern-recognition tasks than a computer. That's where Planet Hunters comes in. Having multiple participants view each image greatly improves the odds of not missing a world.
Keep Reading: The Planet Hunters Site
Source: http://feedproxy.google.com/~r/ziffdavis/pcmag/~3/-8OZLoI4h7E/0,2817,2379660,00.asp
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