Indian Institute of Astrophysics

1. Indian Institute of Astrophysics a premier Institute for Research & Development in Astronomy & Astrophysics Solar Observatory, Kodaikanal (TN):The Kodaikanal Observatory of the Indian Institute of Astrophysics is located in the beautiful Palani range of hills in Southern India. It was established in 1899 as a Solar Physics Observatory and all the activities of the Madras Observatory were shifted to Kodaikanal at 2350 m above MSL. This Observatory is well equipped with a small solar telescope for full disc observataions of Sun, a photoheliograph, a Spectro-heliograph and K-Filtergraph. A 60-cm dia mirror coelostatmounted on 11 m tower platform directs sunlight via a flat mirror into a 60m long underground horizontal `tunnel‘ to form a 34 cm diameter solar image at the focal plane. Spectrographic and spectro-heliographic observations are taken continuously and we have a more than 100 years of valuable Solar data using different techniques during the period of time. A digital archive is set up for providing access to the world community. Discovery of Evershed Effect: Evershed effect refers to the phenomenon of characteristic Doppler shifts of photospheric spectral absorption (Fraunhofer) lines observed over the penumbrae of sunspots. This discovery by John Evershed early in 1909, was through a high dispersion spectrograph that he designed and built at the Kodaikanal Solar Observatory. John Evershed, with his experiment at Kodaikanal Observatory and Solar Plasma Photographs. Postage Stamp released by Govt. of India to commemorate 100 years of Evershed Effect.