Marc Chun: Taking out the Twinkle

As light from a star travels through Earth’s atmosphere, atmospheric turbulence makes stars appear to twinkle, blurring the stars and erasing fine detail.

Astronomers can tune out much of the blurring with adaptive optics (AO), a system that uses sensors and adjustable mirrors – moving more than a thousand times a second inside the telescope – to detect the light beam’s wave front, sharpen the image and bring it back to focus.

In 1988, a team led by Francois Roddier discovered a new way to measure starlight distortion, and designed a curvature deformable mirror system, Hokupa‘a (“immovable star” in Hawaiian). Hokupa‘a was used to commission the Gemini North telescope in 1999.

Its successor, Hokupa‘a-85, was designed and built at the IFA by a team led by Mark Chun and Christ Ftaclas. Hokupaa-85 was commissioned as the AO system for the Near-Infrared Coronagraph Imager (NICI) on Gemini-South, which searches for and images large Jupiter-like planets around nearby stars..

“Adaptive optics brought us the first images of a system of planets outside of our Solar system. AO has also enabled us to observe the motion of stars around the center in our Milky Way galaxy allowing us to measure the mass of the black hole that resides there.” — Mark Chun