In a rare phenomenon, researchers from the Indian Institute of Astrophysics (IIA) have recorded auroral activity — which is normally witnessed over the North Pole — at Hanle and Merak in Ladakh through the all-sky cameras on November 5, stated a report in The New Indian Express.
Researchers explained that the first was recorded on April 23, 2023, and it was the largest. This one of November 5 was the second largest and was recorded from 10 pm. Hanle is the first Dark Sky Reserve in India and is located 4500 metres above sea level.
“The sky was clear and so the cameras were able to record them very clearly. The red auroral light could be seen towards the northern horizon from 10 PM till midnight of and its intensity peaked around 10:40 pm,” Dorje Angchuk, the Engineer-in-Charge, Indian Astronomical Observatory (IAO), Hanle, told The New Indian Express.
An aurora is a glorious curtain of light that is usually seen at high latitudes like the Scandinavian countries, and they are not expected to occur at lower latitudes. They occur due to the interaction between the Earth’s magnetosphere and the incoming solar wind that carries charged particles and magnetic fields. A Stable Auroral Arc (SAA) is red in colour as opposed to the usual green-blue curtains of light seen from high latitudes, which is why Angchuk explained that it was a rare phenomena, but not exactly an aurora like one witnesses from close to the North Pole.
A similar camera had also recorded the same in Merak, on the banks of Pangong Tso in Ladakh (which is the proposed site of the National Large Solar Telescope), though it was limited by higher mountains towards the North.
IIA researchers explained that this particular auroral activity is linked to the Coronal Mass Ejection (CME) that occurred on the sun two days ago.
P Vamareddy, Assistant Professor, IIA, said, “Such activities do occur once in two days. But we do not get to see it because we are located at a lower latitude and do not have the adequate technology to see it. In this case, the intensity of the light was higher and so it was visible from Hanle, which is at 33 degree North. It was a 140-degree field of view.”
Hanle is at the centre of the Hanle Dark Sky Reserve, and attracts the public for astro-tourism due to its dark blue, clear skies. “We look forward to studying many more auroral activities from Hanle, especially when the Sun is in its active period,” said Professor Annapurni Subramaniam, Director of IIA.