In an astronomical first, scientists have spotted a radiation belt around an ultracool dwarf beyond our solar system. Using a global array of radio dishes, they’ve captured detailed images of this unique extraterrestrial magnetosphere.
For the first time, researchers have observed a radiation belt outside our solar system around an ultracool dwarf, using an array of 39 radio dishes. The images depict a double-lobed structure, reminiscent of Jupiter’s radiation belts, within the dwarf’s magnetic field. This groundbreaking discovery, highlighted in a paper published in Nature, opens new realms for understanding magnetic fields in celestial bodies beyond our solar system.
Radio Telescope Array Unveils Extraterrestrial Radiation Belt
Led by Melodie Kao, a postdoctoral fellow at UC Santa Cruz, an international team of astronomers used a series of 39 radio dishes spread from Hawaii to Germany to capture this celestial marvel. By observing radio-emitting plasma within the magnetic field of an ultracool dwarf, they’ve imaged its magnetosphere, a first for an object of gas-giant size outside our solar system.
Understanding Magnetospheres and Radiation Belts
Magnetospheres are magnetic bubbles surrounding a planet, created by strong magnetic fields. Within these magnetospheres, particles can be trapped and accelerated to near light-speed, forming radiation belts. Earth’s Van Allen belts and Jupiter’s radiation belts are prime examples. The newly discovered radiation belt around the ultracool dwarf outshines Jupiter’s by an impressive 10 million times.
Auroras and the Exoplanetary Magnetic Field
The team also obtained the first image capable of differentiating between the location of an object’s aurora and its radiation belts outside our solar system. The strength and shape of a planet’s magnetic field play crucial roles in its habitability, something that the astronomers will continue to investigate.
Uncovering the Magnetism of Ultracool Dwarfs
The object imaged in this study, known as LSR J1835+3259, resides at the boundary between low-mass stars and massive brown dwarfs. Studying such objects can reveal much about the magnetic fields of this class of celestial bodies, potentially aiding our understanding of exoplanet habitability.
The discovery of this exosolar radiation belt presents a host of research opportunities. Future work can focus on the comprehensive characterization of magnetic fields of brown dwarfs and exoplanets, further refining our understanding of magnetospheres. Additionally, the development of the Next Generation Very Large Array will provide more detailed imaging of extrasolar radiation belts, potentially leading us towards understanding the magnetospheres of Earth-like, habitable planets.