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Three Shining Laser Lines through the Night Sky of Mauna Kea

June 26, 2009

The traditional method for astronomical observation is changing and advancing--from passively catching starlight through a camera attached to a telescope to actively facilitating observations with adaptive optics and lasers. Pictures of three laser beams in the night sky above Mauna Kea show that three large telescopes on Mauna Kea—Subaru, Keck, and Gemini--are operating a laser guide star system to gain higher resolution images of the stars and other objects in space.

How and why does this more sophisticated system of observation work? The turbulence of Earth’s atmosphere limits a ground-based telescope’s ability to resolve the details of stellar images. Adaptive optics measures and corrects for the effects of turbulence in real-time and increases the clarity of images (see the details here). With adaptive optics, Subaru Telescope has improved its “eyesight” by a factor of ten and is helping astronomers reveal clearer images of the universe.

However, to use adaptive optics, we need a guide star near an object star to see its turbulence. When there is no ideal guide star, we use a powerful tool-the laser guide star system-which allows astronomers to create an artificial guide star by emitting a laser into the atmosphere 300,000 feet (90km) near the object-star (see the details here). Subaru Telescope had its first success with its laser guide system in the end of 2006 (see the details here), and Subaru’s adaptive optics development team has been working on upgrading and improving its system.

On the night of June 9, when these laser beams were captured at the same time, bright moon light was lightning up the night sky of Mauna Kea. Dr. Testuharu Fuse, an astronomer at Subaru Telescope, said “Nevertheless, we could successfully take pictures by using long-exposure photographs.” The bright scenery, which seems like daytime in the pictures, is an effect of the bright moonlight.




Figure1: (From left) Subaru Telescope, Keck Telescope 【Photo: Hiroko Komiyama】 (enlarge)

Figure2: (From left) Subaru Telescope, Keck Telescope (2 units), IRTF, CFHT, Gemini North Telescope 【Photo: Tetsuharu Fuse】 (enlarge)


Figure3: (From left) Subaru Telescope, Keck Telescope (2 units), IRTF, CFHT, Gemini North Telescope, UH2.2m Telescope, UKIRT, (storage), 1m Ed Telescope 【Photo: Sebastian Egner】 (enlarge)


Figure4: (From left) JCMT, SMA, Subaru Telescope, Keck Telescope (2 units), IRTF, CFHT, Gemini North Telescope 【Photo: Sebastian Egner】 (enlarge)


Figure5: (From left) Subaru Telescope, Keck Telescope (2 units), IRTF, CFHT, Gemini North Telescope, UH2.2m Telescope, UKIRT, (storage), 1m Ed Telescope 【Photo: Sebastian Egner】 (enlarge)


Figure6: (From left) Subaru Telescope, Keck Telescope (2 units), IRTF, CFHT, Gemini North Telescope, UH2.2m Telescope, UKIRT, (storage), 1m Ed Telescope 【Photo: Sebastian Egner】 (enlarge)



* IRTF:Infrared Telescope Facility
* CFHT:Canada-France-Hawai`i Telescope
* JCMT: James Clerk Maxell Telescope
* UKIRT:United Kingdom Infrared Telescope
* UH2.2m Telescope:University of Hawai`i 2.2m telescope
* SMA:Smithsonian Submillimeter Array
* 1m Ed Telescope:University of Hawai`i Hilo 1m Educational Telescope


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