3.6m Devasthal Optical Telescope

The 3.6-meter Devasthal Optical Telescope is a Ritchey-Chrétien telescope in Nainital district that operates with an active optics system at 2,540 meters (8,333 feet) elevation. Its primary mirror weighs 4.3 tonnes and uses advanced technology to correct atmospheric distortion during observation.

Indian Prime Minister Narendra Modi and Belgian Prime Minister Charles Michel remotely activated the telescope from Brussels on March 31, 2016. The inauguration marked a key step forward for optical astronomy research in Asia.

The observatory takes its name from Devasthal, meaning 'place of gods' in Sanskrit, reflecting the spiritual connection between science and tradition in the Indian Himalayas. Visitors during public tours can see the dome and instrumentation that inspire locals and students alike.

The telescope offers three Cassegrain ports with an optical spectrograph, a CCD imager, and a near-infrared spectrograph for different types of astronomical research. Public viewing sessions are available at certain times, and the mountain road access requires planning and clear weather conditions.

This telescope is the largest in Asia, filling a major gap in the distribution of 4-meter class telescopes across the continent. The facility uses Belgian technology for mirror polishing and optical design, showing international cooperation in large-scale projects.

Location: Nainital district

Elevation above the sea: 2,540 m

Diameter: 3.6 m

Part of: Devasthal Observatory

Website: https://aries.res.in/facilities/astronomical-telescopes/360cm-telescope

GPS coordinates: 29.36094,79.68437

Latest update: December 5, 2025 22:31