Transit planet search reveals doubly-tilted solar sytem http://content.usatoday.com/communities/sciencefair/post/2011/09/transit -planet-search-reveals-doubly-tilted-solar-sytem/1
Planet hunters report a world spotted in transit around its star reveals a second "invisible" planet hides somewhere in its solar system. The second planet possesses a different orbital tilt, making it otherwise undetectable to astronomers. All the planets in our solar system, dwarf planets aside, orbit our sun on mostly the same plane. But the worlds orbiting the star Kepler 19, don't, suggests the new Astrophysical Journal report led by Sarah Ballard of the Harvard-Smithsonian Center for Astrophysics. Some 650 light years away, Kepler 19 possesses one world, Kepler 19b, revealed by NASA's Kepler space telescope. The space telescope unblinkingly looks at more than 100,000 stars out to roughly 3,000 light years from Earth (one light year is about 5.9 trillion miles), looking for dips in starlight caused by "transits" of planets orbiting around them. Kepler 19b orbits its star once about every 9 days and appears twice as big as Earth, making it a "mini-Neptune" class planet. However the planet's orbit possesses one oddity, a five-minute glitch in the timing of its transit's repetition that suggests a companion world must be slowing it down. The companion, Kepler 19c, doesn't turn up in the transit survey, suggesting it must orbit on a different inclination than the first planet. "This invisible planet makes itself known by its influence on the planet we can detect," Ballard says in a statement. The problem is that a host of solutions exist for the nature of Kepler 19c, from a small rocky world on a 5-day orbit to a gas giant world following a 100-day ellipse. "It's like having someone play a prank on you by ringing your doorbell and running away. You know someone was there, even if you don't see them when you get outside," Ballard says. _______________________________________________ Medianews mailing list [email protected] http://lists.etskywarn.net/mailman/listinfo/medianews
