Beijing: A Chinese research team using the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), known as the “China Sky Eye,” has for the first time unambiguously detected millisecond-scale radio bursts from starspot regions. This pioneering discovery offers a novel approach to directly exploring small-scale stellar magnetic fields and provides insights into the origins of stellar magnetic activity, as revealed by the research team.
According to Emirates News Agency, the study led by Professor Tian Hui from the School of Earth and Space Sciences at Peking University has been published in Science Advances. The research addresses a long-standing gap in understanding the small-scale magnetic fields on stars beyond our solar system and offers new perspectives on the mechanisms driving their coronal eruptions and space weather phenomena.
In recent years, FAST has made significant advancements in various astronomical fields, although few studies have concentrated on the magnetic activities of individual cool stars. “Over the past few years, we have been working to open up this new research direction, aiming to leverage FAST’s high spectral/time resolution and its excellent sensitivity to study cool stars,” Tian shared with the Global Times.
The success of this study hinges on FAST’s exceptional sensitivity and its ultra-high time and frequency resolution. Earlier stellar radio observations were limited to time resolutions on the order of hours or minutes, whereas FAST has advanced this to the sub-millisecond level, enabling the capture of subtle, rapid variations in stellar radio emissions. Currently, there are virtually no other instruments worldwide that can match this capability, Zhang Jiale, the first author of the paper, told the Global Times.
Sunspots are localized regions of intense magnetism on the solar surface, and eruptions in these areas can disrupt the near-Earth space environment, affecting the normal operation of satellites and systems related to communications, navigation, and power. Other stars also exhibit similar spot structures, and magnetic activity on some active red dwarf stars can be even more frequent and violent, Zhang explained.
The team is extending its use of FAST to study young solar-type stars, brown dwarfs, and magnetic interactions between stars and their planets, Tian added.