Artificial stars focus of astronomy talk

‘Imiloa Astronomy Center’s next Maunakea Skies program will be held at 7 p.m. Friday, July 19. It will focus on why astronomers benefit from creating artificial stars. Join Dr. Rachel Rampy, W.M. Keck Observatory, for her talk titled “Laser Guide Stars for Adaptive Optics.”

Exploring the universe from the confines of Earth requires sophisticated instruments and human ingenuity. The turbulent atmosphere, which is responsible for twinkling stars, poses significant limitations on the capabilities of large ground-based telescopes. Only in the past two decades has the technology of adaptive optics begun allowing astronomers to overcome this.

The need for a bright star, or reference beacon, for measuring the distortion of the atmosphere originally confined the use of adaptive optics to only about 5 percent of the sky. However, in the past decade the situation has improved dramatically through the use of high-powered lasers to create artificial stars in Earth’s upper atmosphere. These laser guide stars are allowing the clarity provided by adaptive optics to be applied at nearly any location in the sky. This capability is responsible for expanding our understanding of the environment around our galaxy’s central supermassive black hole, and is necessary for direct imaging studies of solar system formation and potentially habitable planets around other stars.

This talk will provide an overview of how adaptive optics technology functions, and describe how it is enhanced by the use of laser beacons. Our understanding of the atomic world and quantum mechanics has been pivotal to the development and optimization of laser guide stars, so a synopsis of the key concepts will be presented. Briefly, some current and future laser systems on Mauna Kea will be discussed.

Dr. Rachel Rampy recently joined the Adaptive Optics team at the W. M. Keck Observatory after completing a Doctorate in Physics at the University of California, Santa Cruz (UCSC), in February 2013. Her doctoral research focused on advancing ground based astronomy by providing an improved means of simulating atmospheric turbulence in the laboratory, and through theoretical investigations of how laser light interacts with mesospheric sodium atoms in the formation of laser guide stars. She holds a Bachelor of Science in Astrophysics, also from UCSC, where her thesis research involved studying X-Ray sources in the center of our galaxy. As the daughter of a chemistry teacher, she received an early introduction to science which fostered a deep fascination with nature. Her position at Keck is the realization of a longtime dream to work with the instruments on Maunakea.

Maunakea Skies program will be hosted by Peter Michaud, Gemini. He will provide observational highlights of the current night sky over Hawai‘i, pointing out prominent constellations and stars one can see during this time of year.

The monthly Maunakea Skies planetarium presentations are held on the third Friday of each month. Cost is $8 for Individual, Dual, Kupuna and Family Members; $6 for Patron Members; Free for Silver, Gold and Corporate Members. Non-member rate is $10. Pre-purchase tickets at the ‘Imiloa front desk or by phone at 969-9703.

‘Imiloa Astronomy Center of Hawai‘i is located at 600 ‘Imiloa Place in Hilo, off Komohana and Nowelo Streets at the UH Hilo Science and Technology Park.


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