MSV-2035 Astronomy Document - Inside Design - FINAL - FINAL

Astronomy & Astrophysics 40 (then) state-of-the-art observing facilities in the country. The establishment of the optical observatories in Kavalur (in the South) and Nainital (in the North) in the late 1960s / early 1970s led to the discovery of the atmosphere around Jupiter's moon Ganymede, the discovery of the outer rings of Uranus, discovery of asteroids, observations of novae and star clusters. Observations of the Sun in the radio region began as early as the 1950s. However, it was with the setting up of the Ooty RadioTelescope operating in the 326.5MHz radio region and the Gauribidanur RadioTelescope operating in the decameter region, both in the 1970s, that radio astronomy developed in a significant manner. The country, in the 1980s, saw the development of the 2.3-m Vainu Bappu Telescope. This indigenous optical telescope was the largest optical telescope in Asia, when commissioned in 1986. The Giant Meterwave Radio Telescope (GMRT), yet another indigenous, world class facility, was built in the following decade. It has been available for observations to the national and international community since 2002. India's first astronomy space missionAstroSat, launched in 2015 is yet another indigenous development widely recognised and appreciated by the international community. The scientific achievements of the country in the field of astronomy and astrophysics has now evolved towards participating in a few frontline international mega-projects proposed to be operational in next fewyears, and also development of state-of-the-art national facilities (see Figure 3). Indian scientists have also made significant contributions to the analysis of data from large survey projects like SDSS, Planck, WMAP, etc. Indian astronomers have also made important contributions using international observing facilities through competitive proposals. India has also progressed in step with the world in providing local repositories of archival observations through platforms like the Virtual Observatory India, the Kodaikanal Solar Observatory Digitized Data Archival System (a repository of data obtained from Kodaikanal for over 100 years), GMRTOnlineArchive (GOA), the ISROScience DataArchive forAstroSat Mission, etc. Theoretical astrophysics is an area where India has made significant contributions, ranging from solar physics, stellar astrophysics, galactic dynamics, to extragalactic astronomy, gravitation and cosmology and gravitational waves. There have also been many contributions in computational modelling of astrophysical processes in all these areas as well as in processing of large data sets. Indian scientists have produced many seminal works, especially in gravitation and cosmology. The works by stalwarts such as Bishveshwar Dutt, V.V. Narlikar, Amal Kumar Raychaudhuri, P.C. Vaidya, C.V. Vishveshwara and Jayant Narlikar stand testimony to this. Indeed, Einstein's paper on General relativity was first translated into English in India. Early work on relativity included that of the collapse of pressureless stars to singularity, on expanding universes and the derivation of the Raychaudhuri equation that showed that anomalies are inevitable in general relativity, which is the basis of singularity theorems given later byHawking and Penrose.Another important work was that of the derivation of a realistic metric representation for stars, accounting for the radiation emitted by stars. One of the most important results underlying the emission of gravitational waves by a blackhole merger is that of quasi-normal modes. This result showed that this radiation depends only on the mass of the black hole for a non-spinning black hole. Later, this was generalised to rotating black holes where it also depends on the spin on the black hole. Astronomers hope to use this to establish the final mass of a black hole with improved observations of gravitational wave signals. Relativistic, direct action-at-a-distance theories in the cosmological context and the conformal theory of gravity are two other areas with significant contributions. We provide below science highlights by Indian astronomers, enumerating key areas where Indian scientists have made significant contributions in the last few decades. Also provided in this section is a brief on the ensemble of astronomy facilities available in the country. MEGA SCIENCE VISION-2035