The First Radiation Belt Spotted Outside of Our Solar System is Being Seen by Astronomers

A coordinated array of 39 radio dishes stretching from Hawaii to Germany was used to capture high-resolution photos of the first radiation belt spotted outside of our solar system by astronomers. photos of continuous, strong radio emissions from an ultracool dwarf show the presence of a cloud of high-energy electrons trapped in the object’s strong magnetic field, which forms a double-lobed structure similar to radio photos of Jupiter’s radiation belts. “By studying the radio-emitting plasma its radiation belt in the magnetosphere, we are literally photographing the magnetosphere of our target. Mélodie Kao, a postdoctoral fellow at UC Santa Cruz and the first author of an article on the new results published May 15 in Nature, stated that that had never been done for something the size of a gas giant planet outside of our solar system.

The Van Allen belts, also referred to as Earth’s radiation belts, are sizable zones of very energetic particles that the magnetic field has trapped from solar winds. The majority of the debris in Jupiter’s belts originates from Io’s volcanoes. The radiation belt that Kao and her team have imaged would be 10 million times brighter than Jupiter’s if you could put them side by side. The “northern lights” are produced when charged particles that are deflected by the magnetic field toward the poles contact with the atmosphere. Kao’s team also created the first image that could distinguish between the location of an object’s aurora and its radiation belts outside of the solar system. This study’s imaging of an ultracool dwarf shows that it lies on the cusp between large brown dwarfs and low-mass stars. While the processes that give rise to stars and planets can differ, Kao noted that the physics within them may be very similar in the fuzzier region of the mass continuum that connects low-mass stars to brown dwarfs and gas giant planets. It is mostly unexplored territory, according to her, to describe the strength and composition of the magnetic fields of this class of objects. Planetary scientists can forecast a planet’s magnetic field’s intensity and structure using numerical models and their theoretical knowledge of these systems, but they haven’t had a solid technique to quickly validate these assumptions.

The strength of the magnetic field can be measured using auroras, but not its shape. The purpose of this experiment, according to Kao, was to demonstrate a technique for determining the forms of magnetic fields on brown dwarfs and eventually exoplanets. A planet’s habitability may be significantly influenced by the strength and configuration of its magnetic field. In addition to factors like the atmosphere and climate, Kao said, “we should also take into account the function of their magnetic fields in maintaining a stable environment when thinking about the habitability of exoplanets. A planet’s interior must be heated enough to contain electrically conducting fluids in order to produce a magnetic field; in the case of Earth, this is the molten iron in the planet’s core. Hydrogen is the conducting fluid of Jupiter, where it is under such intense pressure that it turns metallic. According to Kao, metallic hydrogen likely also produces magnetic fields in brown dwarfs, whereas ionized hydrogen serves as the conducting fluid inside stars. The only target that Kao felt confident would provide the high-quality data required to resolve its radiation belts was the ultracool dwarf.

Evgenya Shkolnik, a coauthor from Arizona State University who has long been researching magnetic fields and planet habitability, said, “This is a critical first step in finding many more such objects and honing our skills to search for smaller and smaller magnetospheres, eventually enabling us to study those of potentially habitable, Earth-size planets.” The team made use of the Effelsberg radio telescope run by the Max Planck Institute for Radio Astronomy in Germany, as well as the High Sensitivity Array, a collection of 39 radio dishes organized by the NRAO in the United States. We are able to create photos with an exceptionally high resolution and observe phenomena that have never been observed before by integrating radio dishes from around the world. According to coauthor Jackie Villadsen of Bucknell University, viewing our image is similar to looking at the top row of an eye chart in California while positioned in Washington, D.C. In order to plan the study and analyze the data, co-first author Amy Mioduszewski of NRAO, together with Villadsen and Shkolnik, relied significantly on their multiwavelength stellar flare knowledge. Kao also stressed that this finding was the result of a genuine team effort. Both the Heising-Simons Foundation and NASA provided funding for this project.

Read More

• A robotic goalkeeper with four legs that uses reinforcement learning
• We Can Use Robots to Assess children’s mental well-being, study suggests
• Interestingly comparable stone tools used by early humans and monkeys