Abstract Details

Name: Manjunath Hegde
Affiliation: Indian Institute of Astrophysics
Conference ID: ASI2017_1293
Title : Long term study of the sun using Kodaikanal H-alpha data archive
Authors and Co-Authors : SUBHAMOY CHATTERJEE (Indian Institute of Astrophysics), DIPANKAR BANERJEE (IIAP) and RAVINDRA B (IIAP)
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : The filaments observed in the Hα line in the solar chromosphere are one of the basic indices of solar activity. Systematic Hα observations have been carried out since 1914 at the Kodaikanal Observatory of IIA , 1919 at the Meudon Observatory (France) (spectroscopic observations), and since 1959 at the Kislovodsk Mountain Astronomical Station of the Main (Pulkovo) Astronomical Observatory of Russian Academy of Sciences. We present Long term variations in the distribution of solar filaments observed at the Kodaikanal Solar Observatory (KSO) from 1914 -2007 which spans nearly 7 solar cycles to compare with sunspot cycle and also filament activity. Synoptic charts are produced from calibrated digitised images. Using a semi automatic technique, filaments are detected from synoptic charts. The data on each filament comprise of its centroid location, area, length and tilt angle. We study time-latitude distribution of filament centroids like butterfly diagram of sunspots. 'Rush to the pole' is clearly seen in butterfly diagram. Distribution of filament length shows log normal distribution. Such a long term digitized H-alpha data series provides us an unique opportunity to probe solar activity cycle.