New light on solar radio bursts
doi:10.1038/nindia.2018.16 Published online 9 February 2018
Analysing data captured by radio telescopes, astrophysicists have gained new insights into the birth of solar radio bursts containing streams of energetic particles that eventually radiate out into space and even to the Earth1.
Since such radio bursts can disrupt satellite-based communications and the activities of power grids, these insights are potentially useful for developing models to better understand space-weather disturbances and devising ways to counter them.
Solar radio bursts originate from the acceleration of electrons in the corona, the outermost part of the Sun’s atmosphere. This region produces undetectable high-energy radiations, but it generates detectable low-frequency radio waves that can be handy in unveiling the secrets of space-weather disturbances.
Using Low-Frequency Array (LOFAR) — an array of radio telescopes located in various countries of Europe and URAN-2, a radio telescope parched in Ukraine — an international research team comprising scientists from the Indian Institute of Science Education and Research, in Pune, India, closely monitored solar radio bursts, particularly type III bursts.
The radio bursts have been observed to generate very-low-frequency radio waves. Snapshots lasting for 10 milliseconds helped identify the source of the radio bursts, which propagate upwards through the tenuous solar corona.
Detailed analyses reveal that the radio burst sources grow rapidly in size as they propagate outwards through the corona – this phenomenon closely resembles the process that makes a car’s headlights appear fuzzy and broadened when viewed through a foggy atmosphere.
1. Kontar, E. P. et al. Imaging spectroscopy of solar radio burst fine structures. Nat. Communications. 8, 1515 (2017)