Space

August 29, 2012

NASA’s Kepler discovers multiple planets orbiting a pair of stars

NASA’s Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. The system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.

Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, this discovery proves that more than one planet can form and persist in the stressful realm of a binary star. The discovery demonstrates the diversity of planetary systems in our galaxy.

Astronomers detected two planets in the Kepler-47 system, a pair of orbiting stars that eclipse each other every 7.5 days from our vantage point on Earth. One star is similar to the sun in size, but only 84 percent as bright. The second star is diminutive, measuring only one-third the size of the sun and less than 1 percent as bright.

“In contrast to a single planet orbiting a single star, the planet in a circumbinary system must transit a ‘moving target.’ As a consequence, time intervals between the transits and their durations can vary substantially, sometimes short, other times long,” said Jerome Orosz, associate professor of astronomy at San Diego State University and lead author of the paper. “The intervals were the telltale sign these planets are in circumbinary orbits.”

The inner planet, Kepler-47b, orbits the pair of stars in less than 50 days. While it cannot be directly viewed, it is thought to be a sweltering world, where the destruction of methane in its super-heated atmosphere might lead to a thick haze that could blanket the planet. At three times the radius of Earth, Kepler-47b is the smallest known transiting circumbinary planet.

The outer planet, Kepler-47c, orbits its host pair every 303 days, placing it in the so-called “habitable zone,” the region in a planetary system where liquid water might exist on the surface of a planet. While not a world hospitable for life, Kepler-47c is thought to be a gaseous giant slightly larger than Neptune, where an atmosphere of thick bright water-vapor clouds might exist.
“Unlike our sun, many stars are part of multiple-star systems where two or more stars orbit one another. The question always has been – do they have planets and planetary systems? This Kepler discovery proves that they do,” said William Borucki, Kepler mission principal investigator at NASA’s Ames Research Center in Moffett Field, Calif. “In our search for habitable planets, we have found more opportunities for life to exist.”

To search for transiting planets, the research team used data from the Kepler space telescope, which measures dips in the brightness of more than 150,000 stars. Additional ground-based spectroscopic observations using telescopes at the McDonald Observatory at the University of Texas at Austin helped characterize the stellar properties. The findings are published in the journal Science.

“The presence of a full-fledged circumbinary planetary system orbiting Kepler-47 is an amazing discovery,” said Greg Laughlin, professor of Astrophysics and Planetary Science at the University of California in Santa Cruz. “These planets are very difficult to form using the currently accepted paradigm, and I believe that theorists, myself included, will be going back to the drawing board to try to improve our understanding of how planets are assembled in dusty circumbinary disks.”

Ames manages Kepler’s ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development.
Ball Aerospace & 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 tenth Discovery Mission and funded by NASA’s Science Mission Directorate at the agency’s headquarters in Washington.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines November 26, 2014

News: When Hagel leaves, new SecDef faces big questions about the military’s futureĀ - President Obama’s new pick to run the Pentagon will face a dizzying set of challenges affecting the Defense Department’s mission, budget and culture. Who will be the next Secretary of Defense?- Following the Nov. 24 surprise announcement from the White House, the...
 
 

News Briefs November 26, 2014

Navy to decommission two more ships in Puget Sound The Navy recently decommissioned the guided missile frigate USS Ingraham at Everett, Wash. It will be towed to Bremerton and scrapped. The Daily Herald reports the Navy also plans to decommission another ship at the Everett homeport and also one stationed in Bremerton. Naval Station Everett...
 
 

NASA airborne campaigns tackle climate questions from Africa to Arctic

NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into how different aspects of the interconnected Earth system influence climate change. NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into...
 

 
Air Force photograph by Rick Goodfriend

16T Pitch Boom reactivated to support wind tunnel tests

Air Force photograph by Rick Goodfriend The Pitch Boom at the AEDC 16-foot transonic wind tunnel (16T) was recently reactivated. This model support system is used in conjunction with a roll mechanism to provide a combined pitch...
 
 

Northrop Grumman supports U.S. Air Force Minuteman missile test launch

Northrop Grumman recently supported the successful flight testing of the U.S. Air Force’s Minuteman III intercontinental ballistic missile weapon system. The operational flight test was conducted as part of the Air Force Global Strike Command’s Force Development Evaluation Program. This program demonstrates and supports assessment of the accuracy, availability and reliability of the...
 
 
army-detector

Scientists turn handheld JCAD into a dual-use chemical, explosives detector

Scientists at the U.S. Army Edgewood Chemical Biological Center at Aberdeen Proving Ground, Md., proved it is possible to teach an old dog new tricks by adding the ability to detect explosive materials to the Joint Chemical Age...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>