Astronomers Spot Afterglow After Two Giant Planets Collided In Distant Star System

Astronomers have detected the dusty afterglow of a massive planetary collision in a star system 3,600 light-years away. The massive collision between two huge icy planets left a doughnut-shaped cloud of vaporized rock and water. 

For the findings, astronomers used NASA spacecraft that monitors the sky for asteroids. The researchers believe that the wreckage of the collision could eventually cool and form a new planet. This will provide an amazing opportunity to watch the birth of a new world in real time and it might explain how planets form, the New Scientist reported. 

The team of astronomers was formed after a curious mind saw the light curve of a star designated ASASSN-21 qj and noticed something strange. The star was located around 3,600 light-years from Earth.

"An astronomer on social media pointed out that the star brightened up in the infrared over a thousand days before the optical fading. I knew then this was an unusual event," Matthew Kenworthy, study co-lead and a researcher at Leiden University, said in a statement. "To be honest, this observation was a complete surprise to me."

The team of astronomers continued to study ASASSN-21 qj for two years and observed how its brightness changed over time. The findings were published on October 11 in the journal Nature. 

The researchers observed how such a collision would take place. Live Science reported that the ASASSN-21qj planets likely collated into a single body after the collision.

"Our calculations and computer models indicate the temperature and size of the glowing material, as well as the amount of time the glow has lasted, is consistent with the collision of two ice giant exoplanets," co-lead author Simon Lock, a researcher at the University of Bristol, explained.

The team continues to observe ASASSN-21qj and its planetary wreckage. They will watch the system over the coming years and they expect that the debris cloud will spread out along the orbit of the destroyed planets. 

"It will be fascinating to observe further developments. Ultimately, the mass of material around the remnants may condense to form a retinue of moons that will orbit around this new planet," study co-author Zoe Leinhardt, an associate professor of Astrophysics at the University of Bristol, said.