Flagstaff, Ariz. — A Lowell Observatory-led research team recently received one full night of observing time with the Keck Interferometer, a near-infrared instrument that combines the largest pair of telescopes in the world. Principal investigator Dr. Gerard van Belle of Lowell Observatory says this is the last call for proposals on the instrument, as it will soon be retired.
With this time, the team will measure the sizes of five to 10 faint, low-mass stars to determine their temperatures and check agreement with predicted sizes from stellar modeling, according to Dr. van Belle. “The twin monster telescopes of the Keck Observatory are necessary for this study,” he explains. The team will make these measurements by using the Keck Interferometer instrument, which joins each of the 10 meter (33 foot) telescopes to achieve the equivalent resolution of a single 85 meter (279 foot) telescope. Other interferometers have similar resolving power, but with smaller individual telescopes, cannot collect enough light to detect these faint stars. “Not only are these targets small – about the apparent size of a grape, a thousand miles away – they’re many times fainter than what the next-best telescope can do.”
“These targets are particularly interesting to learn about, because they’re the easiest candidates to find hosting the smaller, nearby Earth-sized planets,” says Dr. van Belle. The small size of these stars increases the size of signals caused by the influence of planets orbiting them.
For the observing time in early February, Dr. van Belle will be joined at Keck headquarters on Hawaii’s Big Island by co-investigators Dr. Kaspar von Braun of Caltech, and Dr. Tabetha Boyajian of Georgia State University.
The Keck Interferometer is slated for retirement in mid-2012, since it has completed its primary mission of observing zodiacal dust shells enshrouding nearby stars. The ongoing work of the individual Keck telescopes will continue, however, including its planet detection program. Lowell’s Dr. Lisa Prato and Dr. Travis Barman utilize the individual Keck telescopes for their research.
NASA’s share of Keck Observatory time is highly competitive, with an oversubscription ratio of 4 to 1.
Dr. van Belle was one of the original instrument architects on the Keck Interferometer, participating in its development and commissioning from 1996 to 2003 while at NASA JPL.
