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lunes, 15 de octubre de 2012

Astronomy: Citizen Scientists Discover Four-Star Planet with NASA Kepler

Today we’re pleased to announce the discovery of the first confirmed planet discovered by Planet Hunters, and it’s a fabulous and unusual world. Labelled ‘Planet Hunters 1′ (or PH1) in a paper released today and submitted to the Astrophysical Journal, it is the first planet in a four-star system. It is a circumbinary planet – one which orbits a double star – and our follow-up observations indicate that there is a second pair of stars approximately 90 billion miles (1000 Astronomical Units) away which are gravitationally bound to the system.
This is much closer than the nearest stars are to the Sun, so anyone viewing the sky from PH1 would have a spectacular view of all four stars. More importantly, this amazing system will help us understand how and where planets can form – producing a stable planet in a system where four different stars are moving about can’t be easy. This is the seventh circumbinary planet, and the first to be in a quadruple system.
The planet itself has a radius a little more than 6 times that of Earth, making it a little bigger than Neptune. It’s mass is harder to pin down (and being in such a complicated system didn’t help), but we have a definite limit that means it must be no more than half that of Jupiter – so this is definitely a planet.
A huge amount of work went into this discovery (as well as a fair bit of observing time on the Keck and other telescopes), but a lot of the credit should be pointed at the Planet Hunters who made the discovery. It was Kian Jek and Robert Gagliano, working together on Talk that made the initial discovery; there’s a post from them on exactly what happened up already. The paper also credits Hans Martin Schwengeler, Dr. Johann Sejpka, and Arvin Joseff Tan all of whom flagged one or more of the transits before the paper was published! This is great news for us and we’re sure there are more planets hiding in data, both at the main interface and over on Talk. For today, though, we can celebrate the arrival of Planet Hunters 1!
Chris
PS We’ve announced discoveries before, of course – as well as being the first four-star planetary system, this is the first where we’ve been able to obtain not only transit information but follow up with radial velocity measurements, detecting the wobbles of the parent stars as well as the dips in light seen when the planet moves in front of them. This is the gold standard for planet discovery, and so this is officially a planet, not just a planet candidate.
PPS The paper, of course, still has to be refereed. We’ll keep you updated here as that process goes on, but as Meg is presenting the details of the system at the annual Division of Planetary Sciences meeting right now we thought you’d want to know the news as soon as possible. There will be more posts about exactly how PH1 was tracked down later in the week, so watch this space. In the meantime, you might prefer version of the paper, which has been annotated with the ScienceWISE tool in order to help explain some of the more technical language.
http://blog.planethunters.org/2012/10/15/ph1-a-planet-in-a-four-star-system/

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The discovery of planets continues to expand beyond the domain of professional astronomers. A joint effort of amateur astronomers and scientists has led to the first reported case of a planet orbiting a double-star that, in turn, is orbited by a second distant pair of stars.

Aided by volunteer citizen scientists using the Planethunters.org website, a Yale-led international team of astronomers identified and confirmed discovery of the phenomenon, called a circumbinary planet in a four-star system. Only six planets are known to orbit two stars but none of these are orbited by a distant binary.

Coined PH1, the planet was identified by the citizen scientists participating in Planets Hunters, a Yale-led program that enlists the public to review astronomical data from NASA's Kepler spacecraft for signs of planets transits distant stars.

"I celebrate this discovery as a milestone for the Planet Hunters team: discovering their first exoplanet lurking in the Kepler data. I celebrate this discovery for the wow-factor of a planet in a four-star system," said Natalie Batalha, Kepler scientist at NASA Ames Research Center, Moffett Field, Calif. "Most importantly, I celebrate this discovery as the fruit of exemplary human cooperation-- cooperation between scientists and citizens who give of themselves for the love of stars, knowledge, and exploration."

A bit larger than Neptune and thought to be a gas giant, PH1 orbits its host stars every 137 days. Beyond the planet's orbit approximately 900 times the distance between the sun and Earth, a second pair of stars orbits the planetary system.

The research paper submitted to the Astrophysical Journal is scheduled to be presented today at the annual meeting of the Division of Planetary Sciences of the American Astronomical Society in Reno.

To read more about the discovery, visit Planethunters.org.

Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

For information about the Kepler Mission, click here.
 
 
Michele Johnson
Ames Research Center, Moffett Field, Calif.
650-604-6982
michele.johnson@nasa.gov
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com

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