New technique to study solar events that effect Earth’s radio and magnetic fields

Vijay Mohan

Chandigarh, March 11

A simpler technique of getting a clearer picture of the Sun’s corona has been developed by Indian astronomers, which will make it easier to identify solar events that disturb the Earth’s radio and magnetic fields.

Technique involves subtracting the constant background of the solar corona and revealing the dynamic corona to improve the efficiency of identification of coronal mass ejections (CME)

CMEs are solar events in which a large cloud of energetic and highly magnetised plasma erupts from the solar corona into space, causing radio and magnetic disturbances on Earth.

The method, developed by scientists at the Aryabhatta Research Institute of Observational Sciences and the Indian Institute of Astrophysics, has been accepted for publication in the Solar Physics, a peer-reviewed journal. It can also give a clear picture of the characteristics of CMEs and make their study easier, a statement issued by the Ministry of Science and Technology on Friday said.

CMEs are dynamic structures in the solar corona and capable of driving the space weather in near-Earth space. It becomes imperative to separate such structures and visually or automatically identify the CMEs through the radial distances in the images taken using coronagraphs, the statement added.

The density of the outermost layer of the Sun’s atmosphere, the corona, decreases with distance outwards. As the intensity of the corona observed in white light depends on the density of particles in the atmosphere, it decreases exponentially. If the contrast between the constant corona and transient CMEs is not high, detection of CMEs becomes a challenge, according to the researchers.