BENGALURU: In what astronomers are calling “unexpected” but “beautiful surprise”, the Indian Astronomical Observatory (IAO) in Hanle and Merak, Ladakh, captured stunning images of an intense red-coloured aurora on the night of November 5.
The IAO, operated by the Indian Institute of Astrophysics (IIA), Bengaluru, is renowned for its astronomical research and observations.
Auroras, typically observed at high latitudes like Scandinavia, are a breathtaking curtain of light caused by the interaction between the Earth’s magnetosphere and incoming solar wind carrying charged particles and magnetic fields.
“However, what made this sighting exceptional is that this aurora displayed a rare hue. Termed a Stable Auroral Arc (SAR), it appeared in vivid shades of red, contrasting the more common green and blue curtains of light associated with higher latitudes,” IIA said on Wednesday.
The red aurora phenomenon was visible towards the northern horizon from 10pm until midnight on November 5, with its intensity peaking around 10:40pm.
Dorje Angchuk, the engineer-in-charge of IAO, reported this spectacular occurrence, IIA said, adding that the event was not exclusive to Hanle, as multiple locations around the world also witnessed a similar SAR event.
“The images were captured using an All-sky Camera at the IAO, which continually monitors the entire celestial sphere. Merak, another Ladakh-based location on the banks of Pangong Tso, known as the proposed site for the National Large Solar Telescope, also managed to capture this incredible celestial display, although it was partially obscured by the presence of higher mountains in the north,” IIA said.
The unusual auroral activity has been linked to a Coronal Mass Ejection (CME) — massive ejections of plasma and magnetic fields from the Sun’s lower atmosphere, which can affect the Earth as it travels through the solar system — that occurred on the Sun two days prior.
Data from NASA’s space missions indicated a filament eruption from the Sun on November 3 at 10:15am, followed by a ‘Halo’ CME observed after 11:10am, IIA said.
Vemareddy, a solar astronomer and faculty member at IIA, explained that the solar storm hit Earth’s magnetosphere, leading to a Geomagnetic Storm starting around 3:30pm on November 5 and peaking at 1:30am on November 6.
When a CME passes Earth, the interaction between the solar wind’s magnetic fields and Earth’s magnetic field allows energetic particles, such as electrons and protons, to enter the atmosphere near the polar regions. This interaction results in a geomagnetic storm and, in some cases, an aurora.
Although the red SAR event has a slightly different physical process, it too is a result of a geomagnetic storm, IIA said. These interactions are known to impact various aspects of technology, including radio communication, satellite health, and power grids.
“The appearance of such an auroral emission at lower latitudes like Ladakh, situated at 33° North, is a rare and exciting occurrence. Hanle is central to the newly designated Hanle Dark Sky Reserve, known for its exceptionally dark skies, attracting astronomy enthusiasts and astro tourists,” IIA said.
IIA director Professor Annapurni Subramaniam, expressed excitement about studying more such auroral activities from Hanle, particularly during the Sun’s active periods. The allure of rare celestial events like the red SAR aurora continues to enhance the appeal of Hanle as a hub for astro tourism and scientific research.

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