Abstract:
The Indian Institute of Astrophysics has been making optical
observations of the sun for more than a century by taking images of the sun
in continuum to study the photosphere, Ca-K line and H-alpha line in order
to study the chromosphere by using the same instruments which are used
to study the long term variations of the magnetic fields on the sun. The
digitizers have been developed using uniform light sources, imaging optics
without any vignetting in the required FOV and large format 4K 4K CCD
cameras to digitize the data for scientific studies. At the Solar Tower Telescope
we have performed very high resolution spectroscopic observations
around Ca-K line to investigate the variations and delineate the contribution
of various features to the solar cycle variations. Solar coronal studies
have been done during the occurrence of total solar eclipses and with a
coronagraph to study the coronal heating. Here we discuss the systematic
temporal variations observed in the green and red emission profiles using
high spectral and temporal observations during the 2006, 2009 and 2010
total solar eclipses. The TWIN telescope a new facility has been fabricated
and installed at Kodaikanal observatory to continue the synoptic observations
of the sun and a space-based coronagraph is also being designed and
fabricated in collaboration with various laboratories of ISRO (LEOS, ISAC
and SAC) and USO. In this article we present the summary of results of
optical observational programs carried out at Kodaikanal Observatory and
during the eclipse expeditions where authors have played a leading role.
Furthermore, this review is not complete in all respects of all the observational
programs carried out at the Kodaikanal observatory.
