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Scientists using India's Aditya-L1 solar observatory reported small, short-lived brightenings in the Sun's chromosphere that appear hours before a major flare and cluster around the spot where the flare later erupts.
The study examined seven M- and X-class flares and identified 102 pre-flare transients in the Mg II h (2803 A) images taken by the Solar Ultraviolet Imaging Telescope (SUIT).
About 28 per cent of these transients had matching X-ray signatures in data from the SoLEXS and HEL1OS payloads, linking chromospheric activity to the corona above it.
The work was led by the Manipal Centre for Natural Sciences with ISRO and other Indian institutes and was published in the Monthly Notices of the Royal Astronomical Society.
A solar flare is a sudden, intense brightening of a region of the Sun caused by the abrupt release of energy stored in twisted magnetic fields, usually above sunspots. Within minutes the material is heated to millions of degrees and radiation is emitted across the electromagnetic spectrum, from radio waves to X-rays and gamma rays. Flares are graded by their peak soft X-ray output on a logarithmic scale with five classes - A, B, C, M and X - where each class is ten times more powerful than the one below it. X-class flares are the largest and can cause worldwide radio blackouts and long-lasting radiation storms in the upper atmosphere; M-class flares cause brief polar radio blackouts and sometimes minor radiation storms; C-class and weaker flares have few noticeable effects at Earth.
Simple Analogy: Think of a twisted rubber band stretched to its limit. The small brightenings the study found are the tiny snaps of individual strands that give way in the hours before the whole band finally breaks.
Led the study; part of Manipal Academy of Higher Education
Built and operates Aditya-L1; collaborating institution
Collaborating institution on the pre-flare study
ISRO centre for satellite building; collaborating institution
Collaborating institution; associated with SUIT development
GS Paper III > Science and Technology > Space Technology; Awareness in the field of Space
General Awareness > Science and Technology > Indian Space Missions
General Awareness > Current Affairs > Science
General Knowledge > Space and Defence Technology
If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth? 1. GPS and navigation systems could fail. 2. Tsunamis could occur at equatorial regions. 3. Power grids could be damaged. 4. Intense auroras could occur over much of the Earth. 5. Forest fires could take place over much of the planet. 6. Orbits of the satellites could be disturbed. 7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted. Select the correct answer using the code given below:
Answer: 1, 3, 4, 6 and 7 only
The layer of the solar atmosphere above the visible photosphere and below the corona, best seen in lines such as Mg II h.
A point about 1.5 million km from Earth towards the Sun where the combined gravity of the Sun and Earth lets a spacecraft hold station and view the Sun continuously.
A small, short-lived brightening in the solar atmosphere that appears before the main flare, often near the eventual flare site.
Conditions in near-Earth space driven by solar activity that affect satellites, communication, navigation and power grids.