Thanks to NASA's Kepler telescope, the 30-year-old Star Wars Tatooine fantasy is now a fact as it has discovered a new planet some 200 light years away from Earth, which is claimed to be orbiting two stars.

Unlike Tatooine in the movie, the new planet, dubbed Kepler-16b, is cold, gaseous and not thought to harbor life. However, the new discovery demonstrates the diversity of planets that our galaxy possesses, NASA said.


This artist's concept illustrates Kepler-16b, the first planet known to definitively orbit two stars -- what's called a circumbinary planet. The planet, which can be seen in the foreground, was discovered by NASA's Kepler mission. The two orbiting stars regularly eclipse each other, as seen from our point of view on Earth. The planet also eclipses, or transits, each star, and Kepler data from these planetary transits allowed the size, density and mass of the planet to be extremely well determined. The fact that the orbits of the stars and the planet align within a degree of each other indicate that the planet formed within the same circumbinary disk that the stars formed within, rather than being captured later by the two stars. Photo: NASA/JPL-Caltech/T. Pyle

Although researchers have discovered and viewed a planet with two stars for the first time, they are not surprised at the discovery as previous researches did hint at the existence of planets orbiting two stars, also called circumbinary planets. However, there was no clear confirmation until the latest discovery by the Kepler space telescope.

Laurance Doyle of the SETI Institute in Mountain View led a research team that used data provided by the Kepler telescope, which looks for Earth-size planets in or near the habitable zone, the region in a planetary system where liquid water can exist on the surface.

It's an indication of what is possible -- something entirely new and different, something very exotic, said Doyle.


Kepler-16b is a Saturn-size planet circles its twin stars in the constellation Cygnus about every 229 days, NASA said. Photo: NASA

According to scientists, the two stars eclipse each other from our vantage point on Earth. A primary eclipse takes place when the smaller star partially blocks the larger one. Similarly, the secondary eclipse occurs when the larger star blocks its smaller counterpart.

NASA said Kepler detected the planet by observing transits -- where the brightness of a parent star dims. Scientists observed dipping brightness of the system even when the stars were not eclipsing one another. This was something that hinted scientists that there must be a third body in the system.

Scientists noticed that the additional dimming in brightness reappeared at irregular intervals of time, which indicated that each time the planet passed, both the stars were in different positions in their orbit. This was the activity that showed the planet was orbiting not just one, but both the stars, in a wide circumbinary orbit.

This discovery confirms a new class of planetary systems that could harbor life, said Kepler Principal Investigator William Borucki, in a NASA statement. Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now.

The two stars which Kepler-16b orbits are said to be smaller and cooler than our sun. The stars are 20 and 69 percent as massive as the sun, said researchers in their report published online in the Sept. 16 issue of journal Science.

Kepler-16b, which orbits its suns in the constellation Cygnus in 229 days, is comparable to Saturn in mass and size, scientists said.

The discovery of Kepler-16b is one of several key findings this week of worlds beyond in our solar system. In all, four different research teams from Europe and the U.S. have reported finding 74 previously unknown exoplanets, as worlds orbiting other stars are called, according to The Wall Street Journal.