An exoplanet orbiting a double star

Oct 03, 2011
An exoplanet orbiting a double star
An artist's conception of Kepler 16, an exoplanet orbiting two stars. Credit: NASA and Kepler

(PhysOrg.com) -- The Kepler satellite, which has now reported the detection of 1781 candidate exoplanets (a planet around a star other than the sun), has also discovered that at least one of them orbits a double star. Each of the two stars in this new system is smaller than the sun (one is 0.2 solar-masses and the other is 0.69 solar-masses), and the planet, called Kepler 16, actually orbits around both of them (rather than orbiting only one).

A team of eight CfA astronomers, Samuel Quinn, Dave Latham, Guillermo Torres, Matt Holman, Robert Sefanik, Warren Brown, John Geary, and Dimitar Sasselov joined with colleagues to report the discovery of 16 in the latest issue of Science. Kepler detects when they transit across the face of a star, dimming its light slightly and briefly; luckily, in this system the planet transits the face of each of the two stars as seen from Earth. The planet itself has a mass about that of Saturn's, orbits around the pair in 221 days, and has a surface temperature of around -125° Fahrenheit.

There is some popular, dramatic appeal to envisioning a planet with two stars (but, since most stars are binaries, there probably are many planets with two suns in their skies, even though they may only orbit one of them). There are, however, some useful scientific consequences of this system of three objects. In particular, models can determine precisely the masses and orbits of all the bodies.

In this system, the fact that the both stars also implies that it's orbit is closely aligned with the orbit of the two stars. This fact in turn suggests the important conclusion that probably the planet formed at the same time as the stars, rather than having been captured from elsewhere with a resultant that would not likely be co-aligned. These and other details, like the shapes of the orbits, make Kepler 16 a particularly exciting and productive exoplanet probe as astronomers try to piece together how planetary systems are made and evolve.

Explore further: Can astronomy explain the biblical Star of Bethlehem?

Related Stories

Tatooine-like planet discovered (w/ video)

Sep 15, 2011

(PhysOrg.com) -- Although cold and gaseous rather than a desert world, the newfound planet Kepler-16b is still the closest astronomers have come to discovering Luke Skywalker's home world of Tatooine. Like ...

The Kepler Mission

Apr 26, 2010

(PhysOrg.com) -- Since the first planet around another star (an "extrasolar planet") was discovered by SAO astronomers and others in 1989, over 450 extrasolar planets have been found. Their study now comprises a whole new ...

Exoplanetary systems

Jan 07, 2011

(PhysOrg.com) -- There are now about fifty stars known with more than one orbiting planet - they are the exoplanetary equivalents of the solar system. These stellar families are critical to astronomers piecing ...

Two more kepler planets confirmed

Aug 08, 2011

Hot on the heels of confirming one Kepler planet, the Hobby-Eberly Telescope announces the confirmation of another planet. Another observatory, the Nordic Optical Telescope, confirms its first Kepler planet ...

Kepler's astounding haul of multiple-planet systems

May 24, 2011

(PhysOrg.com) -- NASA's Kepler spacecraft is proving itself to be a prolific planet hunter. Within just the first four months of data, astronomers have found evidence for more than 1,200 planetary candidates. ...

Recommended for you

Can astronomy explain the biblical Star of Bethlehem?

Dec 24, 2014

Bright stars top Christmas trees in Christian homes around much of the world. The faithful sing about the Star of Wonder that guided the wise men to a manger in the little town of Bethlehem, where Jesus was ...

Hubbles spies the beautiful galaxy IC 335

Dec 24, 2014

This new NASA/ESA Hubble Space Telescope image shows the galaxy IC 335 in front of a backdrop of distant galaxies. IC 335 is part of a galaxy group containing three other galaxies, and located in the Fornax ...

Image: Multicoloured view of supernova remnant

Dec 22, 2014

Most celestial events unfold over thousands of years or more, making it impossible to follow their evolution on human timescales. Supernovas are notable exceptions, the powerful stellar explosions that make ...

Ultra-luminous X-ray sources in starburst galaxies

Dec 22, 2014

Ultra-luminous X-ray sources (ULXs) are point sources in the sky that are so bright in X-rays that each emits more radiation than a million suns emit at all wavelengths. ULXs are rare. Most galaxies (including ...

When a bright light fades

Dec 22, 2014

Astronomer Charles Telesco is primarily interested in the creation of planets and stars. So, when the University of Florida's giant telescope was pointed at a star undergoing a magnificent and explosive death, ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

aroc91
5 / 5 (1) Oct 03, 2011
Uh...

http://www.physor...net.html

Old news is old. Interesting how this doesn't have an author listed that I can insult.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.