Astronomers have unexpectedly discovered the most massive Neptune-like planet ever (more than four times the mass of Neptune in our solar system), but how the world formed remains a mystery. . Between the rocky planet, which has a mass about the same as Earth, and the gas giant, which has the mass of Jupiter, which is more than 300 times the mass of our planet, lies the size of Neptune, which is only about 17 times the mass of the Earth. There is a world of Previous studies have shown that Neptune-sized planets range from frigid worlds with thick atmospheres of hydrogen and helium, like the Neptune we know and love, to very large masses of water and rocky bundles. It has been shown that there is a wide variety of planets, including planets with high densities. Thinner atmospheres such as exoplanets HD 95338 b, TOI-849 b, and TOI-2196 b. In a new study, astronomers looked at TOI-1853, an orange dwarf star with a mass and diameter about 80 percent that of the Sun. TOI-1853 is located in the constellation Bootes, about 544 light-years from Earth. Using NASA’s Transiting Exoplanet Survey Satellite (TESS), they discovered an exoplanet around a star they named TOI-1853 b.

The newly discovered planet sits about 50 times closer to its star than the Sun and takes only 30 hours to complete one orbit, compared with 365 days for Earth. Because the planet is so close to its parent star, it experiences scorching temperatures, reaching temperatures of about 1,200 degrees Celsius. RELATED: Why are there so few ‘hot Neptune’ exoplanets? The newly discovered planet is about 3.46 times the diameter of Earth and slightly smaller than Neptune, which is about 3.8 times the width of Earth. But when scientists measured the strength of TOI-1853 b’s gravitational pull on its star using Italy’s Galileo National Telescope on La Palma, the exoplanet has about 73 times the mass of Earth. presumed to be. This means that its mass is close to that of Saturn, which is about 95 times that of Earth. Overall, TOI-1853 b is about six times more dense than Neptune and almost twice as dense as Earth. This makes it the densest Neptune-sized planet ever known. “Our results are further proof that exoplanet science is always full of surprises,” study lead author Luca Naponiero, an astrophysicist at the University of Rome, told Space.com. “Decades after our first discovery, we continue to discover truly unique worlds. “The discovery of TOI-1853 b suggests that large planets may contain surprisingly high amounts of heavy elements, much more than previously thought,” Naponiero said. added. “Neptune’s planets show an amazing variety of densities and compositions, but I didn’t expect them to be so compact.” Most exoplanets orbiting near stars like TOI-1853 b are A rocky planet less than twice its diameter. The size of Earth, or the so-called Hot Jupiter. A gas giant that is more than 10 times the diameter of the Earth. Curiously, scientists have found few hot Neptunes like TOI-1853 b, and the phenomenon is called a “hot Neptune desert.”

Conventional theories of planet formation would show that TOI-1853 b shouldn’t have existed, Naponiero said. However, since this is clearly the case, one possibility of this planet’s formation is that it was formed in a catastrophic fashion by collisions between “large protoplanetary planets, such as super-Earths.” Yes, he explained. “These massive collisions would have removed some of the original atmosphere and water, leaving mostly rocks behind. If astronomers don’t find TOI-1853 b’s siblings nearby, it’s possible that the planet’s Another possible explanation for its formation is that it was a giant planet with a highly “eccentric” orbit, ie an elliptical orbit. This would have resulted in regular encounters with the star, and the world would have lost most of its atmosphere, leaving behind a dense core. The proximity of these stars may also have reduced the eccentricity of the planet’s orbit over time, explaining the current circular shape of its orbit. The researchers hypothesized that TOI-1853 b is mostly rocky, surrounded by a small shell of hydrogen and helium that accounts for up to 1% of the planet’s mass. Another possibility is that TOI-1853 b is about 50% rock and 50% water. If that’s true, Naponiero said it would mean that the Earth’s extreme heat could have enriched the atmosphere with water vapor. To really figure out the composition of TOI-1853 b, scientists would need to analyze its atmosphere, Naponiero said.

source: https://www.nature.com/articles/s41586-023-06499-2?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=CONR_PF018_ECOM_GL_PHSS_ALWYS_DEEPLINK&utm_content=textlink&utm_term=PID100052171&CJEVENT=37179c4d495b11ee838b00ad0a18b8fc