As the world turns

As stars appear to circle around the north celestial pole, a new laser at the Gemini North telescope on Hawaii’s Maunakea undergoes rigorous testing, as seen in this image from early October 2019. Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. Chu/J. Pollard 

The International Gemini Observatory, a program of the National Science Foundation’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), is seen testing a new laser which is a critical component in the telescope’s adaptive optics system. Adaptive optics utilize artificial guide stars, produced by a laser, as a reference when compensating for distortions caused by turbulence in the Earth’s atmosphere. The result is ultra-sharp images that rival the view from space. Laser commissioning activities required pointing at specific parts of the sky designed to both test and calibrate the state-of-the-art laser. This image is created from a stack of images that reveal the Earth’s rotation and the colors inherent in the images. The laser is pointing in the direction of Polaris, or the North Star (Hokupa‘a in Hawaiian). The green glow near the horizon is due to airglow from oxygen high in the Earth’s atmosphere.