色情视频

Using data from NASA鈥檚 Kepler Mission, 色情视频 astronomers announced the discovery of two new transiting 鈥渃ircumbinary鈥� planet systems 鈥� planets that orbit two stars.

This work establishes that such 鈥渢wo sun鈥� planets are not rare exceptions, but are in fact common with many millions existing in our Galaxy. The work was in the journal Nature and was presented by William Welsh of 色情视频 at the American Astronomical Society meeting in Austin, Texas, on behalf of the Kepler Science Team.

Light-years away

The two new planets, named Kepler-34 b and Kepler-35 b, are both gaseous Saturn-size planets.

Kepler-34 b orbits its two sun-like stars every 289 days, and the stars themselves orbit and eclipse each other every 28 days. The eclipses allow a very precise determination of the stars鈥� sizes.

Kepler-35 b revolves about a pair of smaller stars (80 and 89 percent of the sun鈥檚 mass) every 131 days, and the stars orbit and eclipse one another every 21 days. Both systems reside in the constellation Cygnus, with Kepler-34 at 4,900 light-years from Earth, and Kepler-35 at 5,400 light-years, making these among the most distant planets discovered.

While long anticipated in both science and science fiction, the existence of a circumbinary planet orbiting a pair of normal stars was not definitively established until , announced by the Kepler Team last September. Like Kepler-16 b, these new planets also transit (eclipse) their host stars, making their existence unambiguous.

When only Kepler-16 b was known, many questions remained about the nature of circumbinary planets 鈥� what kinds of orbits, masses, radii, temperatures, etc., could they have? And, most of all, was Kepler-16 b just a fluke?

With the discovery of Kepler-34 b and 35 b, astronomers can now answer many of those questions and begin to study an entirely new class of planets.

The Kepler Mission is one of many ways 色情视频 faculty are leading innovation and discovery, a key initiative of The Campaign for 色情视频. With a unique focus on the teacher-scholar model, 色情视频 attracts researchers interested in solving the world鈥檚 most pressing problems, while showing students how to provide future solutions. .

First of millions

鈥淚t was once believed that the environment around a pair of stars would be too chaotic for a circumbinary planet to form, but now that we have confirmed three such planets, we know that it is possible, if not probable, that there are at least millions in the galaxy,鈥� said Welsh, who led the team of 46 investigators involved in this research.

Laurance Doyle of the SETI Institute, co-author of this paper and lead-author of the Kepler-16 discovery, further stated, 鈥淲ith this paper, the new field of comparative circumbinary planetology is now established.鈥�

The discovery was made possible by the three unique capabilities of the Kepler space telescope:

• Its ultra-high precision
• Its ability to simultaneously observe roughly 160,000 stars
• Its long-duration near-continuous measurements of the brightness of stars

Additional work using ground-based telescopes provided velocity measurements of the stars needed to confirm that these candidates are really planets.

鈥淭he search is on for more circumbinary planets,鈥� said co-author Joshua Carter of the Harvard-Smithsonian Center for Astrophysics, 鈥渁nd we hope to use Kepler for years to come.

Crazy climate 

A circumbinary planet has two suns, not just one. The distances between the planet and stars are continually changing due to their orbital motion, so the amount of sunlight the planet receives varies dramatically.

鈥淭hese planets can have really crazy climates that no other type of planet could have,鈥� said Jerome Orosz, a co-author from 色情视频. 鈥淚t would be like cycling through all four seasons many times per year, with huge temperature changes.鈥�

Welsh added, 鈥淭he effects of these climate swings on the atmospheric dynamics, and ultimately on the evolution of life on habitable circumbinary planets, is a fascinating topic that we are just beginning to explore.鈥�

Funding for this work was provided in part by NASA and the National Science Foundation.

The full journal article 鈥淭ransiting circumbinary planets Kepler-34 b and Kepler-35 b鈥� by Welsh, et al., in the journal Nature is available at .

For additional information, downloadable slides and full-resolution versions of the artwork, please see .

Also see for detailed information about the Kepler Mission.