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Video: Millions Of Planets Orbiting Double Stars

Sunday, January 15, 2012 9:22
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(Before It's News)

Using data from NASA’s Kepler mission, a team that includes a University of Florida astronomer has discovered two new planets orbiting double star systems, something that had never been seen until last September.  Astronomers using NASA’s Kepler mission have discovered two new circumbinary planet systems – planets that orbit two stars, like Tatooine in the movie Star Wars. Their find, which brings the number of known circumbinary planets to three, shows that planets with two suns must be common, with many millions existing in our Galaxy.

A tally on NASA’s website for the Kepler Mission, a search for habitable plants, lists 21 confirmed planets, 1,235 potential planets and 2,165 eclipsing binary stars. With the help of three SDSU professors, NASA can now boast that they have discovered the first circumbinary planet, Kepler-16b, a planet that orbits two stars.

Credit:  San Diego State University

The newly confirmed planets, called Kepler-34b and Kepler-35b, will be announced in January 11  online edition of the journal Nature, said Eric B. Ford, UF associate professor of astronomy. William F. Welsh, associate professor at San Diego State University, is the lead author on the paper.

Kepler-34b and Kepler-35b both orbit a “binary star.” They are actually a pair of gravitationally bound stars that orbit each other. While the existence of such bodies, called “circumbinary planets,” had long been predicted, they remained just a theory until the team discovered Kepler-16b in September 2011. They dubbed Kepler-16b “Tatooine” because of its resemblance to the two-sun world depicted in the “Star Wars” film series.

 Unlike Tatooine, Kepler-16b is a cold gaseous planet just outside of the habitable zone. While the amount of sunlight we receive on Earth is constant, the amount of sunlight on Kepler-16b can vary up to 10 percent. The temperature on Kepler-16b only reaches a cool 200 Kelvin or -100 degrees Fahrenheit. So, don’t book your ticket just yet because you won’t find Luke Skywalker there. 
A New Class of Planetary Systems: This artistic rendition depicts the Kepler-35 planetary system. In the foreground, Kepler-35b, a Saturn-size world orbits its host stars every 131 days. 
The artistic rendition depicts the Kepler-35 planetary system
Image credit: © Mark A. Garlick / 
“We have long believed these kinds of planets to be possible, but they have been very difficult to detect for various technical reasons,” Ford said. “With the discoveries of Kepler-16b, 34b and 35b, the Kepler mission has shown that the galaxy abounds with millions of planets orbiting two stars.”

The planets were discovered by measuring the star light decrease as the planets pass in front of, or transit, either of the two stars. Kepler also measures the star light decrease when one of the stars passes in front of the other. The mutual gravitational tugs of the stars and planets cause the times of the transits to deviate from a regular schedule, allowing astronomers to confirm the planet and measure its mass.

Both planets are low-density gas giants, comparable in size to Jupiter, but much less massive. Compared to Jupiter, Kepler-34 is about 24 percent smaller in size, but has 78 percent less mass. It can complete a full orbit in 288 terrestrial days. Kepler-35 is about 26 percent smaller, has 88 percent less mass, and completes its orbit around the stars much faster – just 131 days.

The astronomers believe the planets are made primarily of hydrogen and too hot to sustain life.

“Circumbinary planets can have much more complex climates, since the distance between the planet and each star change significantly during each orbital period, the length of an alien planet’s year,” Ford said. “For Kepler-35b, the amount of incoming star light changes by over 50 percent within a single Earth year. For Kepler-34b, each Earth-year brings ‘summers’ with 2.3 times as much star light as winters. Over the course of a year, the change in the amount of sunlight heating the Earth varies by only 6 percent.”

The Kepler-35 System: An artist’s rendition of the Kepler-35 planetary system, in which a Saturn-size planet orbits a pair of stars. 
An artist's rendition of the Kepler-35 planetary system.
Image credit: Lynette Cook /

NASA’s Kepler mission, which began in March 2009, uses a 1-meter space telescope trained on one small portion of the Milky Way for several years. Astronomers analyze data from the telescope for periodic dimming that indicates a planet crossing in front of its host star. The mission’s goal is to find the frequency of Earth-size planets in the habitable zone of their host stars – where a planet might have liquid water on its surface.

Most Sun-like stars in the galaxy are not alone, like the Earth’s sun, but have a “dance partner,” forming a binary system or binary star. Kepler has already identified about 2,165 eclipsing binaries, of the more than 160,000 stars being observed.

NASA originally planned to stop receiving data from the Kepler spacecraft in November 2012.

This artist’s conception shows Kepler-34b, a newfound gas-giant planet that orbits a double-star system. Its two suns are both yellow, G-type stars that swing around each other every 28 days. The planet circles them both in 289 days. The discovery of Kepler-34b and Kepler-35b shows that circumbinary planets are common in our Galaxy.

Credit: David A. Aguilar (CfA) 
“Astronomers are practically begging NASA to extend the Kepler mission until 2016, so it can characterize the masses and orbits of Earth-size planets in the habitable zone. Kepler is revolutionizing so many fields, not just planetary science,” Ford said. “It would be a shame not to maximize the scientific return of this great observatory. Hopefully common sense will prevail and the mission will continue.”

The public can contribute to searching for planets using real Kepler data by visiting, which works with the latest versión of Internet Explorer, Chrome and Firefox. For additional information, downloadable slides, and full resolution versions of artwork after the embargo lifts, please see For more information about the Kepler mission, visit:

Contacts and sources:
Material was also provided by   

Harvard-Smithsonian Center for Astrophysics

Read more at Nano Patents and Innovations


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  • marcos anthony toledo

    In this double star system where would the habitable zone be and how many days would it’s year be?

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