Abstract


  THE MULTI APPLICATION SOLAR TELESCOPE (MAST)

  P. Venkatakrishnan , Udaipur Solar Observatory, paravenk@gmail.com

The Udaipur Solar Observatory, Physical Research Laboratory, had recently installed a 50 cm aperture off-axis Gregorian-Coude telescope on its island observatory in Lake Fatehsagar of Udaipur, Rajasthan, India. The project started with the characterization of the site to determine the Friedís parameter r0. This parameter was used to decide the diameter D of the telescope aperture that can optimally benefit from the deployment of an adaptive optics system with N correction terms (D=3r0 sqrt(N)) . For typical value of r0 = 3 cm and N=36, we get D = 54 cm. Thus the aperture was fixed as 50 cm. The initial optical design of the telescope led to the specifications for the telescope which were passed on to Advanced Mechanical and Optical Systems (AMOS) of Belgium, who manufactured the telescope. The dome is a collapsible dome made of tensile fabric. It was manufactured by Armatic Engineering of Bangalore and installed on to the building on the island. The telescope was transported in knocked down condition to Udaipur campus and then was ferried across the lake on a pontoon manufactured by M/S Unique Engineers of Udaipur. A gantry crane was constructed on the island by M/S Vijay Lakshmi Technomen of Udaipur. This crane was used to lift the boxes on to the island. The same crane was used to place the telescope components in position on to the telescope pier. The telescope was installed in 10 missions by AMOS and tested by USO for onsite acceptance. A committee of experts examined the test results, accumulated over a year, and recommended the acceptance of the telescope on 16 June 2015. The telescope is now operational. The back-end instruments, 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 ISAC and will be soon deployed at MAST. MAST will be used to measure vector magnetic fields of active regions at different heights of the solar atmosphere. It will also be used to study seismic effects of solar flares. MAST can be used for astero-seismology as well, including the study of the effect of stellar flares on stellar intensity oscillations.