image: Georgia State University operates a six-telescope optical interferometric array in California. view more
Credit: Georgia State University
ATLANTA--Scientists at Georgia State University's Center for High Angular Resolution Astronomy (CHARA) have been awarded a $3.9 million grant from the National Science Foundation (NSF) to provide scientists greater access to the CHARA Array telescopes at the Mount Wilson Observatory in California.
The CHARA Array is the largest optical interferometer in the world and provides the most detailed views of stars that have ever been made. It is a collection of six widely separated telescopes that act together as one enormous telescope to attain the resolving power, or the ability to define small details, that is similar to a single telescope with a light collecting mirror of more than 300 meters in diameter, much larger than any existing or planned telescope.
The six telescopes send starlight to a central beam-combining laboratory, where specialized instruments record the interference patterns that are created by the waveforms of light. Astronomers use these measurements to estimate the sizes and shapes of stars and to explore the light from other nearby stars or gas clouds.
CHARA Array observations have given scientists some of the first images of the surfaces and magnetic storms of other stars, determined the sizes of planets orbiting other stars, mapped the orbital motions of stars stripped of their outer layers by the gravitational tug of companion stars and recorded the expanding fireball of gases ejected in a nova explosion.
The CHARA Array has also played a key role in the education of young scientists and graduate students at Georgia State and other institutions in the United States, Australia, France and the United Kingdom. Collaborating scientists have built state-of-the-art instruments and brought them to the CHARA Array. Now with the National Science Foundation's support, access to the CHARA Array will be opened to scientists across the country and around the globe.
"We realized since the beginning of the Array operations that there are enormous opportunities for investigations in areas of astronomy beyond those pursued by Georgia State and collaborating astronomers," said Dr. Theo ten Brummelaar, CHARA Array director at Mount Wilson. "Now with the NSF grant, we will have the means to host a large number of visiting astronomers and to help them with new innovative programs with the Array."
The grant will support several new positions at the CHARA Array, including a visitor support scientist who will guide the new investigators in their work. CHARA staff will host workshops at universities across the country to enable scientists to develop their own programs at the Array. The existing data archive will be made available through the Internet, and a number of technical improvements will be made to ensure the efficient operation of the Array.
Astronomers will apply for CHARA Array access through the National Optical Astronomy Observatory (NOAO) time-allocation process that recommends programs based on a peer review system. Dr. Steve Ridgway, a NOAO scientist and Georgia State adjunct professor, initiated a pilot program several years ago that gave limited access to the CHARA Array. Based on the high demand, he thinks the open access will be welcomed by a large number of astronomers.
"The CHARA Array has deep respect from the scientific community, and the NSF considers it one of their crown jewels among supported programs," Ridgway said.
Georgia State will also benefit from the wider participation in the CHARA Array.
"The new ideas and energy brought to CHARA from scientists around the globe will make the Array a central focus in studies of stars and their planets," said Dr. Douglas Gies, CHARA director in Atlanta. "I envision that our greater engagement with the community will lead to broader collaborations and opportunities for Georgia State faculty and students and a wider appreciation of the research frontiers supported by Georgia State."
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