Full-disk synoptic observations of the chromosphere using Hα telescope at the Kodaikanal Observatory

Abstract

This paper reports on the installation and observations of a new solar telescope installed on 2014 October 7 at the Kodaikanal Observatory. The telescope is a refractive type equipped with a tunable Lyot Hα filter. A CCD camera with size 2k×2k acquires images of the Sun and has a pixel size of 1.21'' pixel-1 and a full field-of-view of 41'. The telescope is equipped with a guiding system which keeps the image of the Sun within a few pixels throughout the observations. The FWHM of the Lyot filter is 0.4Å and the filter is motorized, capable of scanning the Hα line profile at a smaller step size of 0.01Å. Partial-disk imaging covering about 10' is also possible with the help of a relay lens kept in front of the CCD camera. In this paper, we report the detailed specifications of the telescope, filter unit, the installation, observations and the procedures we have followed to calibrate and align the data. We also present preliminary results with this new full-disk telescope.