While astronomers believe that FU Ori’s increase in luminosity is due to more material falling on the protostar from a cloud of gas and dust called a protoplanetary disk, the details remain a mystery.
A huge young planet smoldering in a superheated soup of spinning raw material may explain the mystery of the largest stellar eruption on record. Led by the University of Leicester, scientists have suggested that a planet roughly ten times the size of Jupiter is undergoing “extreme evaporation” near the growing star, with this inferno ripping material from the planet and spewing it onto the star.
They have published their findings in the Monthly Notices of the Royal Astronomical Society. Statistics for such flares in developing solar systems suggest that each could witness as many as a dozen similar planet-wiping events.
The scientists focused their attention on the protostar FU Ori, located 1,200 light-years from our solar system, which brightened significantly 85 years ago and has not yet lost its expected luminosity.
While astronomers believe that FU Ori’s increase in luminosity is due to more material falling on the protostar from a cloud of gas and dust called a protoplanetary disk, the details remain a mystery. Lead author Professor Sergei Nayakshin, from the University of Leicester’s School of Physics and Astronomy, said: “These disks feed growing stars more material, but they also nurture planets. Previous observations provided tantalizing hints. of a massive young planet orbiting very close to this star. Various ideas were put forward how the planet could have fostered such a flare, but the details did not pan out. We discovered a new process that could be called a ‘disc hell’ of young planets.” The Leicester-led researchers created a simulation for FU Ori, modeling a gas giant planet formed far out in the disk by gravitational instability in which a massive disk fragments to form huge clumps more massive than our Jupiter but much less dense.
The simulation shows how such a planetary seed migrates towards its host star very quickly, pulled by its gravitational pull. As it reaches the equivalent of a tenth of the distance between Earth and our own sun, the material around the star is so hot that it ignites the outer layers of the planet’s atmosphere. The planet then becomes a massive source of fresh material that feeds the star and makes it grow and shine brighter.
Study co-author Dr Vardan Elbakyan, also based in Leicester, adds: “This was the first star observed to experience such flares. We now have a couple of dozen examples of such flares from other young stars. that are formed on our planet”. “While FU Ori events are extreme compared to normal young stars, from the duration and observability of such events, observers concluded that most emerging solar systems flare like this a dozen times while the protoplanetary disk It is around”. Professor Nayakshin adds: “If our model is correct, then it may have profound implications for our understanding of star and planet formation. Protoplanetary disks are often called nurseries of planets. But we now discover that these nurseries are not quiet places that The first solar planets were imagined by researchers in the system to be instead wildly violent and chaotic places where many, perhaps even most, of the young planets are burned up and literally eaten by their stars.Now it is important to understand whether other stars flashing can be explained with the same scenario”.