IAO Hanle

Subject – Science and Tech

Context – IAO Hanle: A promising astronomical observatory

Concept –

The Indian Astronomical Observatory (IAO) located at Hanle near Leh in Ladakh is becoming one of the globally promising observatory sites, according to a recent study.
This is due to its advantages of more clear nights, minimal light pollution, background aerosol concentration, extremely dry atmospheric condition and uninterrupted monsoon.
They analysed datasets for the Indian Astronomical Observatory (IAO) in Hanle and Merak (Ladakh), and Devasthal (Nainital) in India, Ali Observatory in the Tibet Autonomous Region in China, South African Large Telescope in South Africa, University of Tokyo Atacama Observatory and Paranal in Chile, and the National Astronomical Observatory in Mexico.
They found Paranal, in Chile, to be the best site in terms of clear skies with around 87% of clear nights in a year. IAO Hanle, and Ali observatories, which are located around 80 km from each other, are similar to each other in terms of clear night skies.
They found that Devasthal has a slightly larger number of clear nights compared to the other sites in the subcontinent but are affected by monsoons for about three months in a year. However, night observations at IAO Hanle from 2m-Himalayan Chandra Telescope (HCT) are possible throughout the year without any interruption due to monsoon