India plans to set up National Large Solar Telescope in Ladakh
Nirmala Sitharaman highlighted efforts to boost the astronomy and astrophysics capabilities of India. The instrument will be complementary to the MAST telescope and the Aditya-L1 mission.
India is building the National Large Solar Telescope (NLST), a two-metre class telescope for detailed studies of the Sun. It will observe in visible and near-infrared wavelengths. The telescope uses a Gregorian design on an alt-azimuth mount, so that it can track the Sun as it moves across the sky. The adaptive optics on board allows for sharp images, with a spatial resolution of 0.1 to 0.3 arcseconds. The telescope will be powerful enough for scientists to see very small features on the Sun, such as magnetic structures, plasma movements and changes in the solar atmosphere. Instruments on the telescope will also be able to track magnetic fields, and capture spectra from multiple solar times.
At night, the same telescope can also be used to observe stars. The telescope will be located near the Merak village close to the Pangong Lake in Ladakh, at an altitude of about 4,200 metres above the sea level. The location is a high-altitude desert with clear skies, low water vapour and stable winds, that provide ideal conditions for observing the Sun over extended periods. These features also make it suitable for high-quality coronagraphy, that involves observing the outer atmosphere of the Sun by occulting the disk. The location also fills a gap in global solar monitoring observatories between Japan and Europe, helping provide continuous coverage of the Sun from the ground.
Project led by Indian Institute of Astrophysics
The NLST project is being led by the Indian Institute of Astrophysics in Bengaluru, with support from other institutions across the country. In the Union Budget 2026, the government announced funding for the upgradation and advancement of the NLST infrastructure to support high-resolution studies of the solar atmosphere and space weather research. This funding is part of a broader plan to strengthen astrophysics in India. The telescope will complement the observations of Aditya L1 mission as well as the MAST instrument in Udaipur. The main goals of the instrument include understanding how solar magnetic fields form and change, as well as drivers of solar activity such as flares and coronal mass ejections.