Udaipur Solar Observatory


Udaipur Solar Observatory is considered as the best solar observing site in Asia. Situated on an island in the FatehSagar Lake, Solar Observatory of Udaipur is among the few in the world that are sited on an island. This observatory was designed as per the model of Solar Observatory at Big Bear Lake in Southern California.

The USO is situated on an island in the middle of the Lake Fatehsagar of Udaipur, Rajasthan, India. The sky conditions at Udaipur are quite favourable for solar observations. The large water body surrounding the telescopes decreases the amount of heating of the surface layers. This decreases the turbulence in the air mass and thereby improves the image quality and seeing. The main objective of obtaining the high spatial and temporal resolution observations of solar photospheric and chromospheric activity is to understand the various dynamic phenomena occurring on the surface of the Sun.

Udaipur Solar Observatory, PRL. The collapsible dome enclosing the MAST is seen on the right side

The recently operationalised Multi Application Solar Telescope’s dome is a collapsible dome made of tensile fabric.  Built by Mechanical and Optical Systems (AMOS) of Belgium, MAST was tested by USO for onsite acceptance. Test results accumulated over a year was examined by a committee of experts and telescope was made operationalised  on June 16, 2015.

The back-end instruments of MAST, developed in-house at USO, include an adaptive optics system and a narrow band imaging polarimeter using a tandem Fabry-Perot etalon pair and LCVR polarimetric module. Another instrument, viz., a spectropolarimeter, has been developed at ISRO Satellite Centre and will be soon deployed at MAST.


Figure 1.  Top row: Chromospheric (left) and Photospheric (right) images of a sunspot taken in H-alpha (656.3nm) and G-band (430.5 nm) wavelengths. The sunspot is part of an active region NOAA# 12356, taken on 04 June 2015, 05:13UT.