seattle — Luke Skywalker’s home planet star wars It’s the stuff of science fiction. But Tatooine-like planets orbiting paired stars may be our best shot at finding habitable planets beyond our solar system.
Many stars in the universe come in pairs.many people should have planets orbiting them (Number: 10/25/21). This means that there are likely to be many more planets orbiting binary stars than orbiting isolated stars like ours. But until now, no one knew whether the environment on these planets was suitable for life to exist. New computer simulations show that, in many cases, life can imitate art.
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Terrestrial planets orbit certain binary star configurations remain in a stable orbit for at least a billion years, the researchers reported Jan. 11 at a meeting of the American Astronomical Society. The researchers propose that this stability could be enough for life to develop, as long as the planet is not too hot or too cold.
Of the planets that hang around, about 15 percent spend most of their time even all the time in the habitable zone — the temperate region around a star where water can remain liquid.
The researchers ran simulations of 4,000 binary star configurations, each with an Earth-like planet orbiting them. The team varied factors such as the relative masses of the stars, the size and shape of the stars’ orbits around each other, and the size of the planets’ orbits around the binary pair.
The scientists then tracked the planet’s motion over a simulation time span of up to 1 billion years to see if the planet stayed in orbit on various timescales that might allow life to emerge.
Planets orbiting binary stars can be kicked out of star systems due to complex interactions between planets and stars. In the new study, the researchers found that for planets in large orbits around stellar pairs, only about one in eight are kicked out of the system. The rest are stable enough to remain in orbit for a full billion years. About one in ten settles in their settlement and remains there.
Of the 4,000 planets the team simulated, about 500 maintained stable orbits, putting them in the habitable zone at least 80 percent of the time.
“The habitable zone . . . as I’ve described it so far, it ranges from freezing to boiling,” said Michael Pedowitz, an undergraduate at Ewing College of New Jersey who presented the study. Their definition was too restrictive, he said, because they chose to model Earth-like planets without atmospheres or oceans. This is easier to simulate, but it also allows for wild swings in temperature as the planet orbits.
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“The atmosphere and oceans do a good job of smoothing temperature changes,” said study co-author Mariah MacDonald, an astrobiologist at the College of New Jersey. Abundant air and water might keep a planet in habitable conditions even if it spends most of its time outside the nominal habitable zone around a binary system.
“Once we add atmospheres, the number of potentially habitable planets increases, but I can’t say by how much,” MacDonald said.
She and Pedowitz hope to build more complex models in the coming months and expand their simulations beyond a billion years and include changes in stars that affect the condition of the solar system as it ages.
The possibility of stable and habitable planets in binary star systems is a timely question, said Jason Wright, an astrophysicist at Penn State University who was not involved in the study.
“then star wars out,” he said, “we don’t know of any planets outside our solar system, and haven’t for 15 years. We now know that there are many, and that they orbit these binary stars. “
These simulations of planets orbiting binary stars could serve as guides for future experiments, Wright said. “It’s an underexplored population of planets. There’s no reason we shouldn’t pursue them, and studies like this probably show us that it’s worth a try.”