Astronomy Picture Of The Day: A Giant Planet Cheated Death… and Then Moved Closer!

 

#Astronomy, #NASA , #Space, #διάστημα, #Earth

Black Hole@konstructivizm

In a plot twist worthy of the best sci-fi, astronomers have uncovered how a massive gas giant not only survived its star’s violent death — but later spiraled inward for a closer orbit around the stellar corpse. Meet WD1856b: a Jupiter-sized behemoth (4–11 times Jupiter’s mass) circling a tiny Earth-sized white dwarf just 80 light-years from Earth. It whips around its dead star every 1.4 days — so close that the planet is roughly eight times larger than the star it orbits. When the original star ballooned into a red giant billions of years ago, it should have swallowed everything nearby. Most inner planets don’t survive that fiery phase (our Sun will eventually engulf Mercury, Venus, and possibly Earth). Yet this giant world lived to tell the tale. How Did It Pull Off the Ultimate Escape?Using NASA’s James Webb Space Telescope (JWST), an international team (led by the University of St. Andrews with Northwestern University astrophysicists) finally cracked the mystery. The planet stayed at a safe distance during the star’s red-giant death throes ~5 billion years ago. Then, 3 to 5.5 billion years later, gravitational nudges from companion stars in the triple-star system pulled it inward. As it migrated closer, intense tidal forces reheated the planet to ~400 K (127°C / 260°F) — way hotter than the faint white dwarf’s light could explain. It’s been slowly cooling ever since. The atmosphere? Rich in methane and hazy clouds, giving it a Titan-like golden hue. JWST even captured a record-breaking transmission spectrum: the planet blocks a whopping 56% of its star’s light. “This is one of the most bizarre planetary systems we know of,” said Christopher O’Connor of Northwestern. “Stellar death is not the end — some planets get a vibrant second act.” A Glimpse of Our Own Solar System’s FutureIn about 5 billion years, our Sun will die and become a white dwarf. This discovery shows that outer planets might not only survive… they could keep evolving for billions of years afterward. As lead researcher Ryan MacDonald put it: “It’s like using a time machine to peer into the distant future of our solar system.” Bottom line: The universe is full of surprises. Even after a star’s dramatic finale, its planets can find new life in the cosmic sequel. (Study published today in Nature) (credit: NASA, ESA, CSA, Ralf Crawford (STScI)) — a gorgeous gas giant with hazy, Titan-like skies orbiting a cooling orange-white dwarf. What a wild ride the cosmos has in store for us!