Keck Observatory to Undergo Upgrade to Optics Systems

Adaptive optics (AO) measures and then corrects the atmospheric turbulence using a deformable mirror that changes shape 1,000 times per second. Initially, AO relied on the light of a star that was both bright and close to the target celestial object. But there are only enough bright stars to allow AO correction in about one percent of the sky. In response, astronomers developed Laser Guide Star Adaptive Optics using a special-purpose laser to excite sodium atoms that sit in an atmospheric layer 60 miles above Earth. Exciting the atoms in the sodium layers creates an artificial “star” for measuring atmospheric distortions which allows the AO to produce sharp images of celestial objects positioned nearly anywhere in the sky. Photo credit: W. M. Keck Observatory/ANDREW RICHARD HARA.

The W.M. Keck Observatory on Maunakea will get a significant upgrade to its adaptive optics (AO) systems to improve research efforts on exoplanets, black holes, Dark Matter and Dark Energy. The upgrade is being made possible through an award by the National Science Foundation (NSF).

“The Keck telescopes were the first large telescopes to be equipped with adaptive optics and subsequently laser guide stars,” said Principal Investigator Peter Wizinowich, chief of technical development at Keck Observatory. “All major astronomical telescopes now have laser guide star AO systems. Despite this competition, Keck Observatory’s AO systems have remained the most scientifically productive in the world. This upgrade will help maintain our science community’s competitive advantage.”

AO systems help remove optical distortions created by Earth’s atmosphere to provide more detailed astronomical images. The upgrade will further improve the clarity of images gathered by the telescope.

To promote STEM (Science, Technology, Engineering, and Mathematics) opportunities for education and workforce development, Keck Observatory will include a postdoc and Hawai‘i college student from the summer Akamai Internship Program to work on the development of the upgrade project.

“Part of Keck Observatory’s mission is to train and prepare future generations so the work continues long after we are gone,” said Jason Chin, a senior engineer at Keck Observatory. “Many of Hawai‘i’s finest students, scientists, and engineers end up working on the mainland away from their families. We want to show them there is a vibrant tech industry in Hawai‘i.”

Keck Observatory’s improved AO system will focus on three fields of scientific study:

1. Characterizing planets around low mass stars through direct imaging and spectroscopy;
2. Testing Einstein’s Theory of General Relativity and understanding supermassive black hole interactions at the center of our Milky Way galaxy;
3. Constraining Dark Matter, the Hubble constant, and Dark Energy via strong gravitational lensing.

“These instrumentation improvements will not only enhance the scientific return of our existing AO system, but it will also provide an excellent platform for future improvements,” said Wizinowich. “We were very pleased to learn that our proposal was successful.”

The upgrade is expected to be completed by the end of 2020.