Brief History

The Vainu Bappu Observatory of the Indian Institute of Astrophysics traces its origin back to the year 1786 when William Petrie set up his private observatory at his garden house at Egmore, Madras, which eventually came to be known as the Madras Observatory. Later it was moved over to Kodaikanal and functioned there as the Kodaikanal Observatory since 1899.

M.K. Vainu Bappu who took over as the Director of the Kodaikanal Observatory in 1960, found a sleepy little hamlet called Kavalur in the Javadu Hills as a suitable site for establishing optical telescopes for observing the celestial objects. This came to be known as Kavalur Observatory. Later on, autonomy was obtained and the Head Quarters moved over to Bangalore with the new name as the Indian Institute of Astrophysics.

Located in Kavalur, 25 km from Yelagiri, this is one of the biggest solar observatories in the area. Normally, permission is required to visit the Observatory, but if you are here between 4 and 6 pm on a Saturday, you are in luck because entry is allowed for all without permission.

The first telescope was of 38 cm (15 inch) aperture, with which astronomical observations were started in 1968 at Kavalur Observatory. The 75 cm (30 inch) telescope has been completely designed and fabricated at the workshops of the Indian Institute of Astrophysics. In 1972 a 1 metre (40 inch) telescope made by Carl Zeiss Jena was installed at Kavalur.

2.3 Metre Telescope

Vainu Bappu's swansong was the 2.3 metre (93 inch) aperture telescope, designed and built within the country. However it was rather unfortunate that Bappu passed away in 1982 and could not see the completion of this telescope.

In a befitting tribute, the then Prime Minister Shri Rajiv Gandhi, at a function held at Kavalur on 6th January, 1986, named the observatory as Vainu Bappu Observatory and the 2.3 metre telescope as

Vainu Bappu Telescope

The telescope is so powerful that it can easily resolve a 25 paise coin kept forty kilometres away. Deep sky observations are carried out with this telescope using a variety of focal plane instruments. The equatorially mounted horseshoeyoke structure of the telescope is ideally suited for low latitudes and permits easy observation near the north celestial pole. The telescope has a F/3.25 paraboloid primary of 2.3 m diameter with the prime focus image scale of 27 arcsec/mm and a Cassegrain focus image scale of 6.7 arcsec/mm. This telescope has been operated as a national facility and attracts proposals from all over the country and some times from outside India.

Scientific Activities

Frontline research is being carried out with the help of the optical telescopes at Vainu Bappu Observatory using several focal plane instrumentational facilities. The ongoing programmes include observations of stars, star clusters, novae, supernovae, blazars, galaxies, optical imaging of gammaray burst fields, stellar populations, solar system objects and many others.

The telescopes at the observatory had started with relatively modest focal plane instruments and later on graduated to more sophisticated ones. These include cameras for fast photography, photoelectric photometers, a singlechannel photoelectric spectrum scanner, a medium resolution spectrograph, a quartzprism calibration spectrograph, infrared photometer, image tube spectrograph, a Universal Astronomical Grating Spectrograph (UAGS from Zeiss), highresolution echelle spectrograph and a polarimeter. Photographic plates were the principal detectors in the early days. Presently the Charge Coupled Devices (CCD) have replaced the photographic plates. Some microprocessorcontrolled photon counting systems were designed and fabricated which have been used in a variety of observational projects. A fibre linked echelle spectrograph is under construction.

On campus maintenance facilities like aluminising plants for coating the telescope mirrors, mechanical and electrical workshops, electronics labs, along with a liquid nitrogen plant are at hand for the smooth functioning of the observatory. Highly advanced technical facilities like SUN workstations are available at the telescopes for handling the CCD data, along with specialised data reduction packages such as IRAF, STSDAS and DAOPHOT. Communication facilities, like email via VSAT satellite connection, are available for all users for the telescopes.

A programme of ultralow dispersion spectroscopy was successfully used to survey stars in the Large Megallanic Cloud (LMC). Of the ten supernovae observed so far, SN1987A in LMC was observed in great detail using the 1m and the 75 cm telescopes despite its low elevation in the southern sky, proving the worth of the geographic location of Kavalur. In fact the observations of the supernova were started within 48 hours of the discovery.

Observational studies of evolved stars, in particular studies related to their evolutionary aspects, carried out at this observatory, have received critical acclaim and international recognition. The observational facilities at this Observatory have yielded many Ph.D theses for the scholars of the Institute as well as of other institutes and universities in the country.

Discoveries

The 1 metre telescope is associated with two unique discoveries in the solar system. In the year 1972, atmosphere was detected around Jupiter's satellite Ganymede and in 1977 rings were discovered around Planet Uranus. In 1984 Kavalur reported the discovery of a thin outer ring around Saturn.

On 17th February, 1988 a new minor planet was discovered using the 45 cm Schmidt telescope. It has been named Ramanujan after the Indian Mathematical genius Srinivasa Ramanujan. This is the first such discovery from India in this century.

Popularising Astronomy

The observatory encourages scientific interactions with the public. Special attention is given to students at various levels. The observatory is open to public on all Saturdays at which time visits to the various telescopes and star watching programmes are organised.