Rare Comet Lemmon Lights Up Bengaluru Sky In Brief Celestial Show

A faint green comet, officially designated C/2025 A6 (Lemmon), was briefly visible over Bengaluru’s western horizon on Saturday evening.

Several people from the city shared photos of the comet on social

media, showing its bright green coma and faint dust tail, visible for just a few minutes before vanishing below the horizon.

“I’m so glad that I witnessed Comet today in the sky @ #Bengaluru,” one user tweeted, while another wrote, “Noticed something in the sky today morning. #Bengaluru #NammaBengaluru.”

Comet Lemmon was first identified in January 2025 by astronomers at the Mount Lemmon Observatory in Arizona, US. It has gradually brightened as it moves closer to the Sun and remains visible to observers in the Northern Hemisphere using binoculars. Its brightness, however, fluctuates as solar heat causes jets of gas and dust to erupt from its surface, a process known as outgassing.

Astrophotographer Deepak Choudhary, founder of the astronomy outreach platform thegreatbeyond.in, captured images of the comet from the rooftop of the Co-Evolve high-rise in Bengaluru using a William Optics Zenithstar 61 refractor telescope. The pictures showed a green coma and a short, faint dust tail visible only briefly before the comet dipped below the skyline.

The comet’s green glow is caused by fluorescence of diatomic carbon (C₂) when exposed to ultraviolet sunlight, not reflection. The gas exists only in the coma and quickly breaks apart, making the tail appear nearly colourless, experts told The Hindu.

Choudhary noted that photographing the comet from a city with dense light pollution was challenging. “The window to image was just a few minutes before it dropped too low. Urban astrophotography is about precision more than location,” he told the publication.