Astronomers study the source of last year’s most intense geomagnetic storm


n late April 2023, an intense geomagnetic storm in Earth's magnetosphere caused a visible display of auroras in lower latitudes, extending to places such as Ladakh. Was. Astronomers have used multiwavelength observations from several space telescopes to trace the origins of storms in the Sun. They found that the rotation of the filament structure when close to the Sun was the main reason behind this solar storm resulting in such a strong impact on the Earth.

Normally the Sun emits ionized gas (plasma) and magnetic fields into interplanetary space in the form of coronal mass ejections (CMEs). When these CMEs encounter planets like our Earth, they interact with the planets' magnetic fields resulting in large magnetic storms. Accelerated particles and geomagnetic storms can have adverse effects on human technology installed on Earth and in space. Thus, understanding and predicting coronal mass ejections (CMEs) is of both scientific and practical importance.

At midnight (Indian Time – IST) on April 21, 2023, a massive CME burst erupted from 'active region 13283' located near the solar disk center, resulting in the most intense geomagnetic storm of Solar Cycle 25. This CME was launched at a high speed of about 1500 km/second and on April 23 at 12:30 pm Indian time, it encountered the near-Earth atmosphere. As a result, a geomagnetic storm began on Earth just an hour later. The storm reached its peak magnetic field and was classified as “G4 Severe”. The resulting aurora was captured by all-sky cameras located at the Indian Astronomical Observatory in Hanle, Ladakh, which is operated by the Indian Institute of Astrophysics.

Data collected in research by the Indian Institute of Astrophysics, an autonomous institute under the Department of Science and Technology, published in The Astrophysical Journal, helped identify (track) the source of the storm in the Sun.

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