Ca-K Observations

The Kodaikanal observatory have been acquiring photoheliograms of the Sun, at the 3933.67 Å, since 1904 on daily basis using a 15 cm aperture telescope. Details on the instrument, calibration etc. are described in Priyal et al 2014bSolar Physics, 289, 137

These plates have been used for polar network Index identifications by Priyal et al 2014a, ApJ, 793, 4 and also for automated plage identification by Chatterjee et al, 2016.

Butterfly Diagram from Kodaikanal Plage data

Image of Butterfly Diagram from Kodaikanal Plage data
Click here for a 3-D view of the butterfly diagram

This data has also been used by Mandal et al 2016 to establish the one-to-one connection between the sunspot and the plages.

Carrington maps

Recently Chatterjee et al, 2016 have used the digitized Ca-K images to construct the Carrington maps for the 100+ years of data. All the Carrington maps can be accessed from here .

Observation Statistics of Ca-K (1904-2011)

Ca-K Prominence Observations:

Using the same set up used for Ca-K data by blocking the disc observations are carried out since 1904. Distribution of the data set is shown below.
    Ca K prominence histogram