Cold planet discovered in the "forbidden zone" of the universe

Researchers determined that WD 1856+534b has a mass about 5.2 times that of Jupiter and a surface temperature of -52°C, making it the coldest exoplanet ever observed in direct light.

Astronomers have made a groundbreaking discovery by confirming the existence of an icy planet orbiting a white dwarf star in a region of space known as the "forbidden zone" - where planets normally cannot exist.

The white dwarf star WD 1856+534, located 82 light-years from Earth in the constellation Draco, is 5.8 billion years old. In 2020, NASA's TESS satellite, along with several ground-based observatories, discovered an object the size of Jupiter orbiting the star every 1.4 days.

Recently, a research team led by Dr. Mary Anne Limbach of the University of Michigan used the James Webb Space Telescope to confirm that the object, named WD 1856+534b, is indeed a planet. Notably, the planet is located very close to its host star, 30 times closer than the distance between Mercury and the Sun.

When low- to medium-mass stars like the Sun run out of nuclear fuel, they swell into red giants before expelling their outer layers and leaving behind a dense core — called a white dwarf. Typically , planets within a radius of two astronomical units, or the “forbidden zone,” are destroyed in the process, scientists say.

By analyzing signals received from the James Webb Telescope, researchers determined that WD 1856+534b has a mass about 5.2 times that of Jupiter and a surface temperature of -52°C, making it the coldest exoplanet ever observed in direct light.

However, it is still not the coldest known planet, as the planet OGLE-2005-BLG-390Lb near the center of the Milky Way has a surface temperature of about -223°C.

Scientists believe that WD 1856+534b originally had a more distant orbit and moved into the "forbidden zone" after its host star stabilized into a white dwarf, possibly due to the gravitational influence of another planet or star./.

(Vietnam News Agency/Vietnam+)

Source: https://www.vietnamplus.vn/phat-hien-hanh-tinh-lanh-gia-trong-vung-cam-cua-vu-tru-post1038364.vnp