Twice the mass of Earth, new planet orbits one star in a two-star system

An international team of astronomers has discovered a planet orbiting just one star in a two-star system — a dynamic duo not only strikingly similar to our Earth and sun but also key to the continuing evolution of planetary formation science.

The team’s research, published in the July 4 edition of Science, details a planet twice the mass of Earth and similar in its orbit as the primary component of a relatively close binary system, which typically involves two stars orbiting each other as a pair, according to Texas A&M University astronomer and exoplanet expert Darren DePoy.

“The planet is interesting because of the similarity with its mass and orbit relative to its star being about the same as ours,” DePoy said. “Because the star is much less luminous than the sun, however, the planet is cold.”

DePoy says the planet, called OGLE-2013-BLG-0341LBb, is in the Milky Way Galaxy, in the disk about halfway to the center and quite a long way off — about 3,000 light-years from Earth.

“We are observing the target with the Spitzer Space Telescope, which should allow us to determine a more precise distance, given that the satellite is relatively far from the Earth and has a different perspective on the event,” he added.

While DePoy admits there are other “similar to Earth” systems in the universe (“although not many,” he is quick to add), he says this finding is unusual and unprecedented due to the new light it sheds on previous planetary formation models.

“Theory used to predict planets wouldn’t form in binaries, because the two stars would disrupt the material from which planets could form by not allowing that material to condense and to gravitate together,” DePoy said. “This more or less demonstrates that is incorrect and gives the theorists something to think about.”

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