Deformation measurement on large telescope in Chile

Application of the Absolute Multiline Technology under extreme conditions

Two astronomy telescopes with extreme dimensions are currently under development: The European Extremely Large Telescope (E-ELT) and the Giant Magellan Telescope (GMT).
To monitor the relative mirror location under different operating conditions, Etalons Absolute Multiline System was tested on the already existing Very Large Telescope (VLT) in the Atacama Desert in Chile.

The system successfully demonstrated its capability to measure the movement of the secondary mirror in relation to the primary mirror over 12 meters. Deformations caused by temperature and gravity could be determined accurately. When the telescope dome was opened, the measurement ability of the system was not impaired by temperature changes and wind. The results of successful measurements will be presented by researches from ESO and GMT at an astronomy conference in June.

Photo: S.Guisard (ESO)