Abstract:
A review of modernization and growth of ground
based optical and near-infrared astrophysical observational
facilities in the globe attributed to the recent technological
developments in opto-mechanical, electronics and computer science areas is presented. Hubble Space Telescope
and speckle and adaptive ground based imaging have
obtained images better than 0.1 arc sec angular resolution
bringing the celestial objects closer to us at least by a factor
of 10 during the last two decades. From the light gathering
point of view, building of large size ([5 m aperture) ground
based optical and near-infrared telescopes based on latest
technology have become economical in recent years. Consequently, in the world, a few 8–10 m size ground-based
optical and near-infrared telescopes are being used for
observations of the celestial objects, three 25–40 m size are
under design stage and making of a *100 m size telescope
is under planning stage. In India, the largest sized optical
and near-infrared telescope is the modern 3.6-m located at
Devasthal, Nainital. However, the existing Indian moderate
size telescopes equipped with modern backend instruments
have global importance due to their geographical location.
Recently, the Government of India approved India’s participation in the thirty meter telescope project.
