Astronomy and Astrophysics Progress in India

Manzoor A. Malik

Astronomy in India has a glorious past. There are documented evidences that Astronomy was studied in India from the Vedic times dating back to 1500 BC and then nurtured in the fifth and sixth century AD by the greats like Aryabhatta, Varahamihira, Brahmagupta that continued even when Europe was passing through the dark ages. The advent of telescopes shifted the leadership in Astronomy studies from Asia and Middle East to Europe. Even though Maharaja Jai Singh in the beginning of 18th century had erected a chain of five observatories in India, it remains a mystery as to why he didn’t set up telescopes in those observatories. The beginning of telescope aided astronomy can be ascribed to the commissioning of the Madras observatory by East India Company in 1792. Besides some noteworthy observations, a catalogue of positions of over 11,000 stars was completed using this observatory.

Modern day astronomy in India flourished after it gained independence. An inspiring article by the Nobel laureate C. V. Raman that appeared in the 1943 issue of Current Science might have made an impact. In that article he mentions that Astronomy is the cultural heritage of India and Indians would be unworthy recipients of that heritage if Astronomy as a science is not promoted. As on date, numerous institutes in India are doing frontline research in Astronomy and Astrophysics. The leading ones include: Indian Institute of Astrophysics (IIA), Bangalore; Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune; Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital; Tata Institute of Fundamental Research (TIFR), Mumbai; National Centre for Radio Astrophysics (NCRA-TIFR), Pune; Indian Institute of Science (IISc), Bangalore; Raman Research Institute (RRI), Bangalore; Physical Research Laboratory (PRL), Ahmadabad; Harish-Chandra Research Institute (HRI), Allahabad. Besides, Institute of Mathematical Sciences (IMSc), Chennai, some of the Indian Institute(s) of Technology (IIT), Indian Institute(s) of Science Education & Research (IISER) and several universities are actively engaged in astronomy and astrophysics research and teaching.

IIA hosts a 2-m optical infrared telescope, the world's highest observatory for optical & infra-red astronomy, situated at an altitude of 4500 meters above sea level. The cloudless skies and low atmospheric water vapor make it one of the best sites in the world for optical, infrared, sub-millimeter, and millimeter wavelengths. Another, 2.3 m telescope (VBO) is located in Kavalur, Tamil Nadu. The Kodaikanal Observatory of the Indian Institute of Astrophysics was established in 1899 as a Solar Physics Observatory. The Gauribidanur Observatory, a radio astronomy facility, mainly focuses on the observations of the Sun. IIA is also in the process of establishing a state-of-the-art solar telescope (NLST) which will permit Indian scientists to carry out cutting edge research aimed at understanding the fundamental processes taking place in the Sun. NLST will be the largest solar telescope in the world and would fill the longitude gap between Japan and Europe. The preferred location is Pangong lake site (in Ladakh) owing to excellent "seeing" conditions there. The main research areas pursued at IIA are Sun & Solar System, Stellar & Galactic Astronomy, Extragalactic Astronomy & Cosmology, Space Astronomy, Instrumentation, and Theoretical Astrophysics & Physics.

IUCAA, though only a quarter of a century old, is fast emerging as a leading research institute in theoretical astrophysics, cosmology and in observational astronomy. Besides the core academic programs, IUCAA has a vibrant visitor academic programme aimed to promote the nucleation and growth of active groups in astronomy and astrophysics at Indian universities. Current active areas of research include: Cosmology and large scale structure, Galactic and extragalactic astronomy, Classical and quantum gravity, Cosmic magnetic fields, Gravitational waves, High energy astrophysics, Instrumentation for astronomy, Interstellar medium, Optical astronomy, Radio astronomy, Solar Physics. IUCAA hosts a 2-metre optical and near-infrared telescope and is a key player in some of the major upcoming facilities like TMT, LIGO and ASTROSAT.

TIFR has a well-established department of Astronomy where cutting edge research in theoretical and observational astrophysics including instrumentation is carried out. The research interests of the department can be broadly categorized into three groups: X-Ray and Gamma Ray astronomy; Infrared and Optical astronomy; and Theoretical astrophysics. The observations are carried out using ground based facilities as well as balloon-borne and satellite-borne instruments. NCRA, the radio astronomy facility set up by TIFR at Pune, has an active research program in many areas of Astronomy and Astrophysics, which includes studies of the Sun, interplanetary scintillations, pulsars, the Interstellar medium, active galaxies and cosmology. NCRA operates the Giant Meter wave Radio Telescope (GMRT), which is the largest Radio Telescope operating at low radio frequencies. It is an open access facility and is used by astronomers across the world. NCRA also operates a large Cylindrical Telescope known as the Ooty Radio Telescope (ORT).

ARIES has a unique geographical position (79° East) that places it at almost in the middle of 180° wide longitude band, between Canary Island (20° West) and Eastern Australia (157° East), and therefore complements observations which might not be possible from either of these two places. This has resulted in some unique contributions like optical observations of the afterglow of gamma-ray burst, a few micro-lensing events and quasar variability, new ring systems around Saturn, Uranus, and Neptune were also discovered. The Institute hosts two telescopes of apertures 1 and 1.5 meters and is in the process of setting up of a 3.6 meter optical telescopes at Devasthal, a site known for excellent observing conditions. The research activities of ARIES in the field of Astronomy and Astrophysics mainly hinge around Asteroseismology, Binary stars, Galactic and extra-galactic astronomy, Instrumentation for astronomy, Polarization, ISM, Dust, Solar system, Star-formation and stellar evolution, Transient objects - Gamma-ray burst, Supernovae and Variable stars.

The first dedicated Indian astronomy satellite, ASTROSAT, is being developed at ISRO (Indian Space Research Organization) and is scheduled to be launched in May 2015. The satellite is designed for the study of cosmic sources simultaneously over a wide range of the electromagnetic spectrum; from optical bands to high energy X-rays. This simultaneous multi-wavelength capability will allow ASTROSAT to make very important contributions in many areas of Astronomy, particularly in the simultaneous multi-wavelength monitoring of intensity variations in a broad range of cosmic sources, the X-ray sky for new transients, sky surveys in the hard X-ray and UV bands, studies of periodic and non-periodic variability of X-ray sources, broadband spectroscopic studies of X-ray binaries, AGN, SNRs, clusters of galaxies and stellar coronae.

While India has a world class observing facility at radio wavelengths (GMRT) and is soon launching the ASTROSAT, with multi-wavelength capabilities in the X-ray and UV domain, similar powerful facilities in the optical and infrared domain are inadequate. Though Indian astronomers have been using some of the existing 5-10 m class international facilities, only three 2 m class optical-IR telescopes exist in India to be supplemented by a 3.6 m telescope to be commissioned soon. Motivated by the limited access to the high end observing facilities and the near impossibility of building a large optical observational facility of its own, India has ventured into the TMT project as a key player. IIA, ARIES and IUCAA are leading the efforts of Indian astronomical community in this venture. India is contributing 10% of the estimated $1.5 Billion project mainly in kind in the form of preparing key parts of the primary mirror system, developing software, making actuators and sensors that will locate where one mirror is with respect to its neighbors. Being partners (rather than guest observers) in the TMT project with a resolution 12 times better than the Hubble Space Telescope, Indian astronomical community will enjoy a level playing field with leading international astronomers besides mastering technology to build large facilities of their own.

Another major involvement is in the Laser Interferometer Gravitational-wave Observatory (LIGO) project. Among the three gravitational-wave detectors presently located in USA, the plan is to move one of these detectors to India where site survey has been already carried out. The strategic importance of the third LIGO detector being set up in India is that it offers the longest baseline possible on earth. A consortium of several institutes in India have come under a single banner called IndIGO (Indian Initiative in Gravitational-wave Observations) to evolve a strategy towards turning the Indian gravitational-wave initiative into reality. The science benefits of this experiment are enormous given the multi-disciplinary nature of the experiment. It will attract and benefit scientists and engineers from fields like optics, lasers, gravitational physics, astronomy and astrophysics, cosmology, computational science, mathematics and various branches of engineering.

The next major upcoming facility is the India-based neutrino observatory (INO). It is an underground facility to study fundamental issues in science especially neutrino oscillations. INO laboratory’s design permits it to also host a dark matter decay experiment. In fact, DINO (dark matter at INO) experiment is being set up inside the underground INO laboratory.

Further, the success of Chandrayaan-1 mission that found evidence of water molecules on the moon, perfect launch of the Mars orbiter spacecraft making it the first Indian made object to leave the Earth's sphere of influence and other major initiatives like these have opened up a host of opportunities for space exploration using indigenous technology. Space mission Chandrayaan-2 that will orbit the moon and send a small robotic car to the lunar surface, ADITYA-1, a solar observation spacecraft, are also planned. The economics of Indian space missions make them especially attractive e. g. Indian Mars mission cost about one tenth of NASA’s Mars mission.

India is marching ahead in Astronomy research aided by ground based, balloon borne and satellite facilities. The future of Astronomy in India is bright and the next decade promises a substantial contribution coming from India.

Professor Malik is on the faculty of the Department of Physics, University of Kashmir, Srinagar, Jammu and Kashmir, India

---

Disclaimer - The articles and opinion pieces found in this issue of the APS Forum on International Physics Newsletter are not peer refereed and represent solely the views of the authors and not necessarily the views of the APS.