A study led by astronomers at the Indian Institute of Astrophysics traced the variation of the Sun's magnetic activity with latitude of almost eleven years using a new technique. This was done using calcium K line spectroscopic data from the Kodaikanal Solar Observatory which recently celebrated its 125th anniversary.

This study was published in The Monthly Notices of the Royal Astronomical Society as a paper titled "Variations of the Ca II K line profile parameters with solar latitude and time observed from Kodaikanal Solar Observatory", by Apoorva Srinivasa, Anu Sreedevi, K P Raju, K Nagaraju, Jagdev Singh, Narayanankutty Karuppath, P Devendran, T Ramesh Kumar, P Kumaravel.

The paper can be downloaded from here.

The PIB press release is here.

The DST press release is here.