MSV-2035 Astronomy Document - Inside Design - FINAL - FINAL

Astronomy & Astrophysics 66 A 20-cm refractor, operated in the H wavelength. The telescope can be operated in two modes, (a) full disc mode with spatial resolution of 1.24"/pixel and (b) partial disc or high resolution mode with 0.49"/pixel. The Udaipur Solar Observatory (USO) located on an island in the middle of lake Fathesagar in Udaipur provides excellent conditions for observations of the Sun. There are twomain instruments operating at the observatory: The Multi-Application Solar Telescope (MAST), an off-axis Gregorian afocal telescope with a clear aperture of 50-cm with a field de-rotator to compensate the image rotation and a guider to track the Sun continuously. It also has a wave front sensor for correcting optical misalignments caused due to temperature variations. The potential of the MAST is realised through specialised back-end instruments, a narrow–band imager to record simultaneous images of the photosphere and chromosphere, a polarimeter to measure the magnetic fields in sunspots and an adaptive optics system for image stabilisation and to achieve diffraction-limited performance. The Global Oscillation Network Group (GONG) instrument that is part of a community-based international programme to conduct a detailed study of solar internal structure and dynamics using helioseismology. USO is one of the sites of the six-station network of extremely sensitive, and stable velocity imagers located around the Earth to obtain nearly continuous observations of the Sun's “five- minute” oscillations, or pulsations. Gauribidanur Radio Observatory was established in 1976 and is used primarily for observations of the Sun in the decameter wave radio region. The observatory consists of: Adecametre wave radio telescope (GEETEE) consisting of 1000 dipoles arranged in a 'T' configuration, with a 1.4 km East-West arm and a 0.5 km South arm. It has been engaged in the study of radio waves at 34.5 MHz emanating from Sun and various other diverse objects in the sky. This facility provided the first two-dimensional images of radio emission from slowly varying discrete sources in the outer solar corona. A radioheliograph (GRAPH) to obtain two dimensional images of the solar corona simultaneously at different frequencies in the range 40 - 150 MHz. The frequency coverage of GRAPH is unique that it provides useful information on the solar corona in the height range 0.2 - 0.8 Rs above the solar surface (Rs = radius of the Sun), which at present is difficult to observe at other frequencies in the electromagnetic spectrum. No other radio telescope, dedicated for solar observations, is presently operational in the above frequency range anywhere in the world. Ahigh resolution radio spectrograph (GLOSS) that is used in conjunction with the GRAPH for obtaining dynamic spectrum of the transient emission from the solar corona. The GLOSS and the GRAPH together provide spectral and positional information on eruptive solar activity, again a unique combination. The Gauribidanur Radio Interferometric Polarimeter (GRIP) is an east-west one-dimensional array of 40 • • • • • • • α MEGA SCIENCE VISION-2035