ALPAO supplied all the deformable mirrors to equip the auxiliary telescopes that form part of ESO’s Very Large Telescope Interferometer (VLTI) array at the Paranal Observatory in Chile.

A major improvement has been settled with the installation of the New Adaptive Optics Module for Interferometry (NAOMI) on each of its 1.8-meter Auxiliary Telescope (AT). This long-waited upgrade allows the astronomers to reconstruct exquisite images of even fainter objects, like young pre-main sequence stars and their protoplanetary discs, post-main sequence mass-losing stars, and active galactic nuclei. The four NAOMI modules arrived on Paranal in the first half of 2018.

ALPAO deformable mirror (DM) is the masterpiece of the NAOMI system. By using such an advanced adaptive optics system, NAOMI will improve the precision of the measurements performed by the VLTI and achieve a better and more stable image quality. It will its change shape about 500 times per seconds in order to actively counteract the damaging effect of wind and turbulences on the image quality. Interestingly, the ALPAO DM is also able to shift the image of the star further away, few times per second, in order to monitor the brightness of the sky itself. This technique, called ‘chopping’, is absolutely needed for the forthcoming MATISSE instrument which will observe the far infrared light.

“On some nights it looks like the atmosphere is virtually gone! We can now observe much fainter objects,” explained Julien Woillez, the VLTI Project Scientist, on their latest public announcement. “With NAOMI, we can now use cutting-edge second-generation instruments like PIONIER, GRAVITY, and MATISSE to their full potential.”