A gigantic exoplanet dubbed WD 1586 b has been discovered orbiting a white dwarf, a dead star. It’s the first recorded instance of this phenomena, according to a study published in the journal Nature.
The planet, which is outside of our solar system, is about 80 light-years from Earth and roughly the size of Jupiter (approximately 318 times larger than Earth).
WD 1586 b whips around its dead star which is located in the Draco constellation, completing an orbit every 34 hours. Earth takes a year to orbit the Sun.
The white dwarf, which is about the size of Earth, is the remnant of a much larger star that expanded for billions of years into a red giant until it collapsed and, most likely, consumed several planets in its path.
Researchers believe WD 1586 b survived the star dying because it was originally much further away by was pulled into its current orbit during the star’s evolution from red giant to white dwarf.
Ian Crossfield, study coauthor and assistant professor of physics and astronomy at the University of Kansas, told CNN that the star probably died 6 billion years ago.
Crossfield added that the researchers found the planet by looking through data collected by NASA’s Transiting Exoplanet Survey Satellite (TESS), which launched in 2018.
“TESS finds a planet by looking at a star, and it measures how bright the star is continuously for weeks,” Crossfield said. “If a planet is orbiting the star, and if the planet passes between you and the star, some of that star’s light is going to be blocked. Then the star will get brighter again as the planet passes — we call this the ‘transit’ of the planet.”
“In around five billion years our Sun will become a white dwarf,” Crossfield said. “There’s a lot of open questions about whether planets can survive the process of a star inflating up to become a red giant, swallowing up some of the inner planets, and then shrinking back down and just being left over as the white dwarf again.”
“Can planets actually survive that — or is that impossible? And until now, there weren’t any known planets around white dwarfs.”
While a white dwarf cools over billions of years, it still emits light and heat, which could make a planet in a close, tight orbit, the “sweet spot,” potentially inhabitable.
“This tells us white dwarfs can have planets, which is something we didn’t know before,” Crossfield said. “There are people who now are looking for transiting planets around white dwarfs that could be potentially habitable. Now we at least know some kinds of planets can survive and be found there, so that gives greater support and greater interest in continuing the search for even smaller planets around these white dwarfs.”
Star, White dwarf, Orbit, Jupiter, NASA, Earth, Exoplanet
World news – GB – Giant planet found orbiting dead star 80 light-years from Earth