A novel technique for tracking solar eruptions that disrupt space weather will be used in India’s first solar mission. Scientists have developed this unique method to track the huge bubbles of gas threaded with magnetic field lines ejected from the Sun. Such phenomena cause adverse conditions in space weather, like geomagnetic storms, that can cause satellite failures and power outages.
Ejections from the Sun, technically termed Coronal Mass Ejections (CMEs), cause various disturbances of the space environment which can seriously affect space travel. As such, forecasting their arrival is extremely critical to the success of any space mission. However, forecasting accuracy is hindered by limited CME observations in interplanetary space.
Identifying and tracking solar eruptions in a huge number of images can become tedious if done manually. Compounding this, the advancement in space technology has led to a tremendous increase in the amount of data obtained from spacecraft.
Until recently, a software programme named Computer Aided CME Tracking Software (CACTus) based on a computer vision algorithm has been used to detect and characterise such eruptions automatically in the outer corona where these eruptions cease to show accelerations and propagate with a nearly constant speed.
However, this algorithm could not be applied to the inner corona observations due to the tremendous acceleration experienced by these eruptions. This has severely limited the capability to track the eruptions as CMEs accelerate in the lower corona.
Research led by Mr Ritesh Patel, Dr Vaibhav Pant, and Prof. Dipankar Banerjee from Aryabhatta Research Institute of observational sciences (ARIES), Nainital, an autonomous institute under DST, Government of India, along with their collaborators from Royal Observatory of Belgium, have led to the development of another algorithm that overcomes this challenges.
CMEs Identification in Inner Solar Corona (CIISCO) can be used to detect and track the accelerating solar eruption in the lower corona. CIISCO has been successfully tested on several eruptions observed by space observatories, including Solar Dynamics Observatory and Solar-Terrestrial Relations Observatory, PROBA2/SWAP launched by NASA and ESA, respectively.
The parameters determined by CIISCO have been proven to be useful to characterise these eruptions in the lower corona, a region where the properties of such eruptions are less known. Scientists are confident that the implementation of CIISCO on the large volume of data available from space observatories mentioned above will be helpful to gain a better understanding of eruptions in the inner corona.
The use of automated detection algorithms, like CIISCO, can potentially be used to provide early warnings of CMEs if a EUV telescope is located at ± 90∘ from the Sun-Earth line, providing CME characteristics and kinematics close to the sun.
India’s first solar mission, Aditya-L1, will be observing this region of the solar corona. Deployed on Aditya-L1, CIISCO-obtained data will provide new insight into the CME properties in this less explored region.
Aditya or Aditya-L1 is India’s spacecraft mission to study the sun. It has been designed and will be built in collaboration between the Indian Space Research Organisation (ISRO) and various Indian research institutes. It is planned to be launched on the PSLV-C56 in December 2021 or January 2022.
Originally meant to only observe the solar corona, Aditya-L1 can now provide observations of sun’s corona (soft and hard X-ray, Emission lines in the visible and NIR), Chromosphere (UV) and photosphere (broadband filters). In addition, particle payloads will study the particle flux emanating from the sun and reaching the L1 orbit. The magnetometer payload will measure the variation in magnetic field strength at the halo orbit around L1. These payloads have to be placed outside the interference from the earth’s magnetic field as they would not have been useful in the low earth orbit.
