First Light for Laser Guide Star Technology Collaboration

A team of astronomers and engineers from ESO, the Instituto de Astrofísica de Canarias (IAC), the Gran Telescopio CANARIAS (GTC) and INAF Osservatorio Astronomico di Roma has achieved first light and successful commissioning of the ESO Wendelstein Laser Guide Star system [1] at the IAC’s Observatorio del Teide on Tenerife in Spain.

Following an agreement in April 2014 between ESO and the IAC, the required infrastructure for the experiment was built at the observatory. The team carried out the installation and commissioning of the ESO Wendelstein Laser Guide Star Unit laser, the receiver system and the automated observing software.

These joint activities are research and development studies to optimise the laser guide star return brightness from the upper atmosphere with special attention being paid to the influence of the geomagnetic field on the performance.

The experimental setup uses fibre laser technologies developed at ESO to produce a 20-watt continuous wave laser that is capable of varying laser parameters such as frequency, spectral lines, linewidth, polarisation and intensity. The setup allows laser guide stars to be acquired automatically while switching the laser parameters and the pointing. Observational campaigns will start in February 2015 and continue at a rate of one week per quarter for a period of 15 months.

This work is part of a larger laser guide star and adaptive optics technology research and development programme at ESO in collaboration with Member State institutes and companies, in the context of current and future large telescope projects including the European Extremely Large Telescope (E-ELT). These experiments are also a step towards the development of the laser guide star system for the GTC and could be adopted to upgrade existing systems at other telescopes such as the Large Binocular Telescope.

Notes

[1] These laser systems are some of the technology used in the technique of adaptive optics, which compensates for the atmospheric turbulence that affects ground-based observations. An artificial guide star is produced by shining a powerful laser into the sky — which acts as an artificial reference point from which light is returned back to Earth — helping to create images of astronomical objects as sharp as if the telescope were in space.

Courtesy of European Southern Observatory