Kodaikanal Astrophysical Observatory

the national observatory of India, located in Kodaikanal in the state of Tamil Nadu (formerly Madras). Situated at an elevation of 2,343 m in the Palni Hills, it was founded in 1899 in order to study the connection between solar activity and meteorological phenomena. Its most important fields of research are solar physics, solar survey, solar-terrestrial relations, stellar physics, meteorology and seismology, and geomagnetic and ionospheric observations. Its instruments include a solar telescope of original design (a coelostat in an 11-m tower and a 36-cm underground refractor with three spectrographs), a magnetograph, three spectroheliographs, a spectrohelioscope, a 20-cm coronagraph, radio telescopes (at 100 and 3,000 MHz), a 51-cm reflector, and a transit instrument. The observatory publishes Bulletin (since 1905).