Abstract:
Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV; 130 – 180 nm),
Near Ultra Violet (NUV; 200 – 300 nm) and Visible band (VIS; 320–550nm) imagers. ASTROSAT is a first multi
wavelength mission of INDIA. UVIT will image the selected regions of the sky simultaneously in three channels &
observe young stars, galaxies, bright UV Sources. FOV in each of the 3 channels is ~ 28 arc-minute. Targeted angular
resolution in the resulting UV images is better than 1.8 arc-second (better than 2.0 arc-second for the visible channel).
Two identical co-aligned telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of ~375 mm diameter)
collect the celestial radiation and feed to the detector system via a selectable filter on a filter wheel mechanism; gratings
are available in the filter wheels of FUV and NUV channels for slit-less low resolution spectroscopy. The detector
system for each of the 3 channels is generically identical. One telescope images in the FUV channel, and other images in
NUV and VIS channels. One time open-able mechanical cover on each telescope also works as Sun-shield after
deployment.
We will present the optical tests and calibrations done on the two telescopes. Results on vibrations test and thermovacuum
tests on the engineering model will also be presented
