The researchers discovered a gas planet orbiting white dwarfs at close range, according to a September 16 report in the journal Nature.
Simulation of gas planet WD 1586 b and a white dwarf. Photo: CNN.
This exoplanet is outside the solar system, is the size of Jupiter and is named WD 1586 b. It orbits the body of a star as large as Earth in a 34-day orbit. Compared to WD 1586 b, Mercury is the closest planet to the Sun and takes 90 days to complete an orbit. WD 1586 b is located in the Draco star cluster, 80 light-years from Earth.
A white dwarf is a remnant of a sun-like star, which bulges into a red giant during evolution. The red giant burns off hydrogen fuel and expands, “devouring” any planets near it. For example, when the Sun becomes a red giant in a few billion years, it will destroy Mercury, Venus and possibly Earth. After the star loses its atmosphere, all that’s left is the core. It becomes a white dwarf and cools over billions of years.
Finding an intact planet orbiting close to a white dwarf raises questions about how it appeared there and survived the star’s evolution. Researchers believe that the planet is very far away from its host star and closer after the star evolved. Their simulations show that as the star becomes a white dwarf, the planet gets closer and closer. The results of the study hypothesize that large planets can survive the intense evolution of a star.
“We think this star died and became a white dwarf about 6 billion years ago, long before the formation of the solar system,” said Ian Crossfield, assistant professor of physics and astronomy at the University of Kansas. study co-author, said. “Even though the star is only 1 / 10,000 as bright as the Sun, the WD 1586 b is in a stable orbit. It will be there so we can dig deeper for many years to come.”
NASA’s transitional exoplanet survey satellite (TESS) launched in 2018 and specializes in searching for planets orbiting nearby stars. The team noticed WD 1586 b while looking up data collected by TESS. To confirm it’s a planet, Crossfield used the Spitzer Space Telescope before the mission ends in January of this year. Spitzer is designed to look with infrared rays and look at invisible objects in the visible range of light.
Subsequent terrestrial telescope observations also helped confirm the discovery. After confirming the planet, the team ran a simulation to determine how close it was to its host star. If the red giant “swallows” the nearby planet, this destabilizes the orbit of the further Jupiter-sized planet, causing it to follow an oval orbit and get closer to the white dwarf. cycle. By