They survived the transformation from a star to a red giant The James Webb Infrared Space Telescope has directly observed two exogiant candidates surrounding two metal-contaminated white dwarf stars. If this discovery is further confirmed, it would be the oldest known exoplanet ever directly observed. This in turn indicates that giant planets in wide orbits can survive the final stages of stellar evolution. A preprint of this study is available at arXiv.org. More than 5,000 exoplanets are currently known, but scientists still have little observational data on exoplanets around evolved stars. In theory, planets close to the star would be destroyed by tidal forces or absorbed by red giants, but outer planets (those orbiting farther than the solar system’s main asteroid belt) could survive and move into more distant orbits. may move to. Traces of exoplanets, or planetary material as a polluting component of the white dwarf’s atmosphere, have also been found near white dwarfs. Using a space telescope, a team of astronomers led by Susan E. Mullally of the Space Exploration Institute says they have discovered two exoplanet candidates in the form of two point infrared sources around two dirty white dwarf stars. reported. It was created as part of direct observations of dwarf stars using his MIRI instrument in February 2023 and James Webb in July 2023. Dwarf stars WD 1202-232 and WD 2105-82 were chosen as targets, and their hydrogen atmospheres show signs of accumulating metal-rich material. WD 1202–232 is 34 light-years from the Sun, has a mass 1.3 times the mass of the Sun, formed 900 million years ago, and has a total age (the age of the star before leaving the main sequence plus the cooling age). (added) is 500 million years, 3 billion years. WD 2105−82 has a mass of 2.5 solar masses, is located 52.7 light-years from the Sun, and took 830 million years to form, giving the star a total age of 1.6 billion years. WD 2105-82 is also magnetized, with a magnetic field strength of approximately 50 kilogauss at the poles. Exoplanet candidate WD 2105-82b is in a circular orbit with a radius of 34.62 AU and a period of 243 years around the dwarf star, and its mass is estimated to be 1 to 2 times that of Jupiter. If the star is on the main sequence, the planet can be 9.7 AU away from the star. WD 1202-232b has a mass between 1 and 7 times that of Jupiter and is in a circular orbit with a radius of 11.47 astronomical units and a period of 50 years. If a star is on the main sequence, a planet can be 5.3 astronomical units away from it.

source: https://arxiv.org/abs/2401.13153