Scientists have figured out why Jupiter did not turn into a star

Scientists have figured out why Jupiter did not turn into a star
Scientists have figured out why Jupiter did not turn into a star

Scientists using computer simulations have found that brown dwarfs originally formed like stars, and gas giants - like planets.

Brown dwarfs are space objects with masses ranging from 0.012 to 0.077 solar masses, or 13 to 80 Jupiter masses. They share characteristics with both planets and stars, which is why they are sometimes referred to as sub-stars. They are larger than the giant planets, but not massive enough to shine like real stars. Past research has shown that brown dwarfs orbiting stars likely formed themselves as low-mass stars. As in stars, nuclear fusion occurs in their depths, but after the exhaustion of the reserves of the nuclei of light elements, thermonuclear reactions stop.

American astronomers led by Brendan Bowler of the University of Texas at Austin, using live images from ground-based telescopes in Hawaii - Keck Observatory and Subaru Telescope, studied the orbits of such satellites orbiting their stars in 27 planetary systems.

Modern technology makes it possible to obtain direct images of objects with a mass of 1 Jupiter mass. However, it is not always clear whether a large object found on the outer edge of a particular planetary system is a giant planet or a small brown dwarf.

“As technology has improved, one of the most important questions that arose - what is the nature of the satellites that we find? - Brendan Bowler's words are given in the Keck Observatory press release. orbits. Their orbits today are the key to uncovering their evolution."

But observing the orbital rotation of gas giants and brown dwarfs is a very long process. They are so far from their stars that one revolution can take hundreds of years. Since most of the objects have been discovered in the past one to two decades, scientists have images corresponding to only a few percent of the total orbit of each.

Using a system of adaptive optics, scientists have taken pictures of giant planets and brown dwarfs, capturing with high accuracy their current movement around their parent stars. Then, combining this data with all previous observations published by other astronomers or available in the archives of telescopes, they performed computer simulations. As a result, a set of possible variants of orbits for each satellite was obtained.

"Any, even small movement gives a cloud of possible orbits, - the scientist notes. - The smaller the cloud, the closer the astronomer approaches the true orbit of the satellite."

Using the specially designed program Orbitize !, which uses Kepler's laws of motion, the researchers checked which types of orbits correspond to the measured positions and which do not.

“Instead of waiting decades or centuries for the planet to complete a revolution, we can compensate for the short time frames of our observations with very accurate measurements of position,” said another study participant, Eric Nielsen of Stanford University. developed specifically for partial orbits, allowed us to find orbits even for satellites of the longest period."

Finding the shape of the orbit is key in determining the type of object. Those with more circular orbits probably formed like planets, and those with elongated orbits like stars. In the latter case, the star-forming cloud of gas and dust at one time split into two parts - from one a star was formed, from the other a brown dwarf orbiting this star. Scientists say they are, in fact, binary star systems that contain one real star and one "failed" one.

The main result of the study, according to the authors, is that they were able to show that giant planets and brown dwarfs formed fundamentally differently.

"Although these satellites are millions of years old, the memory of how they formed is still encoded in their current orbits," Nielsen notes.

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