The star exhibited an unusual brightness surge 85 years ago and continues to outshine its anticipated luminosity.
Scientists, guided by the University of Leicester, put forth a thrilling theory of a gigantic planet caught in a fiery dance of destruction to elucidate the largest stellar eruption ever observed. Their study proposes a Jupiter-sized planet, tenfold larger, enduring intense evaporation near an evolving star, with the ensuing cosmic inferno tearing away the planetary material and throwing it onto the star. The exciting findings found their place in the Monthly Notices of the Royal Astronomical Society.
Analysis of stellar flares in nascent solar systems hints at each system potentially experiencing a dozen such planet-devouring phenomena. Researchers zeroed in on the protostar FU Ori, situated 1,200 light-years away from our solar system. It exhibited an unusual brightness surge 85 years ago and continues to outshine its anticipated luminosity.
Exoplanet Caught in Fiery Dance: The Conundrum of FU Ori
The specifics remain elusive despite astronomers’ belief that FU Ori’s radiance hike results from additional material descending on the protostar from a gas and dust-filled protoplanetary disk. “These disks not only fuel the growth of stars but also feed planets,” stated Professor Sergei Nayakshin, lead author of the study from the University of Leicester’s School of Physics and Astronomy.
Previous sightings gave suggestive clues of an enormous young planet in a close orbit around this star. Although several theories were proposed on how the planet might have instigated such a flare, the specifics remained unresolved.
Simulating a Fiery Cosmic Dance
The Leicester team proceeded to simulate a scenario for FU Ori, envisioning a gas giant birthed in the disk’s outer regions by gravitational instability. In this phenomenon, a substantial disk disintegrates to form gigantic clumps exceeding Jupiter’s mass but with significantly lesser density.
The simulation painted a grim picture of the planetary seed being swiftly drawn toward the host star due to gravitational attraction. On reaching a tenth of the distance between Earth and our Sun, the surrounding material ignites the planet’s atmospheric outer layers due to intense heat. Consequently, the planet transforms into a colossal source of fresh material that fuels the star, amplifying its growth and brightness.
Observations of Stellar Flares
“This was the inaugural star spotted experiencing such flares. We now have a series of similar flare observations from other young stars,” shared study co-author Dr Vardan Elbakyan, also from Leicester. Although FU Ori events are extreme for typical young stars, such phenomena’ frequency and observable traits led observers to conclude that most emerging solar systems experience around a dozen similar flares.
“If our model holds, it could revolutionize our comprehension of star and planet formation,” Professor Nayakshin added. Traditionally, protoplanetary disks are hailed as planet cradles. The recent findings, however, paint a picture of chaos and violence where many juvenile planets are incinerated and devoured by their stars. It’s now crucial to discern whether other stellar flares follow the same narrative.