Lots of Tatooine like planets around binary stars may be habitable

Seattle – Luke Skywalker’s home planet Star Wars science is a fictitious material. But a Tatooine-like planet in orbit around a pair of stars may be the best for us in our search for habitable planets beyond our solar system.

Many stars in the universe come in pairs. And lots of them must have planets orbiting them.SN: 10/25/21). In this way, there may be more planets orbiting binaries than there are around single stars like ours. But until now no one had a clear idea of ​​whether the environment of those planets could be conducive to life. New computer simulations suggest that in many cases life can imitate art.

Some configurations of binary stars orbiting Earth can remain in stable orbits for at least billions of years, researchers reported on January 11 at a meeting of the American Astronomical Society. This kind of stability, the researchers propose, is enough to allow life to develop if the planets are not too hot or too cold.

Of the planets that stuck around, about 15 percent remained in the habitable zone—the temperate region around their stars where liquid water could remain—most or even all of the time.

The researchers are running simulations of 4,000 binary star configurations, each with a planet in orbit around it. The clusters are as varied as the relative masses of the stars, the sizes and shapes of the orbits of the stars around each other, and the size of the orbits of the planets around the binary.

Scientists then tracked the motions of the planets for millions of simulated times to see if the planets stayed in orbit over the kinds of periods that would allow life to emerge.

A planet orbiting a binary star can be kicked out of a star system due to the complex interactions between the planet and the star. In a new study, researchers found that only about 1 in 8 planets with large orbits around pairs of stars have been kicked out of the system. The rest were stable enough to continue a full orbit for billions of years. About 1 in 10 habitable zones lived and stayed there.

Of the 4,000 planets that the team had simulated, about 500 maintained stable orbits that kept them in habitable zones at least 80 percent of the time.

“The habitable zone . . . as I’ve characterized it so far, spans from freezing to boil,” said Michael Pedowitz, an undergraduate student at the College of New Jersey in Ewing who conducted the research. Their definition is too narrow, he said, because pla- they chose to imagine the earth without an atmosphere or oceans.

“The atmosphere and the ocean would moderate temperature variations quite well,” says study coauthor Mariah MacDonald, an astrobiologist also at the College of New Jersey. An abundance of air and water would potentially allow the planet to maintain habitable conditions, even if it would spend more time outside the nominal habitable zone around the binary star system.

The number of potentially habitable planets will increase once we add atmospheres, says MacDonald, but I can’t say how much yet.

She and Pedowitz plan to build more sophisticated models in the coming months, as well as extend their simulations beyond the 1,000-year period and include changes in the stars that can affect conditions in the solar system as they age.

The possibility of stable, habitable planets in binary star systems is a timely issue, says Penn State astrophysicist Jason Wright, who was not in the study.

“In time” Star Wars They went out, he says, of any planets outside the solar world, we did not know for 15 years. Now we know there are many more, and they orbit these binary stars.”

These simulations of orbiting binary planets could serve as a guide for future experiments, says Wright. This population of planets has been explored under. It’s not that we can’t follow after them, and studies like this show us that it’s worth the effort.