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Updated: Jun 12, 2026

Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
Active optics control of VST telescope secondary mirror
Pietro Schipani1, Sergio D'Orsi, Davide Fierro
1Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Naples, Italy. schipani@oacn.inaf.it
Abstract:
In telescopes based on active optics, defocus and coma are usually compensated for by secondary mirror movements. They are performed at the Very Large Telescope Survey Telescope (VST) with a hexapod--a parallel robot with six degrees of freedom positioning capability. We describe the application of the two-mirror telescope theory to the VST case and the solutions adopted for the hexapod control. We present the results of performance and reliability tests performed both in the laboratory and at the telescope.
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