June 4, 2013
Low-Budget Ground Telescope Pinpoints Gas Giant Exoplanet
Lee Rannals for redOrbit.com — Your Universe Online
Scientists announced during the American Astronomical Society´s (AAS) national meeting in Indianapolis this week that they have discovered a hot Saturn-like planet in another solar system 700 light-years away.
The team used an inexpensive ground-based telescope to discover KELT-6b, which resides in the constellation Coma Berenices near Leo. This exoplanet has an orbit that transits its star every 7.8 days. Because of the length of the orbit around its star, the team had to patiently wait seven hours while continuously observing the sky to catch the planet's transition of its host star.
Karen Collins, a University of Louisville doctoral student, said KELT-6b is now the longest duration full planetary transit continuously observed from the ground.
The KELT North telescope in Arizona briefly glimpsed the new planet last year, but the team needed help with follow-up observations to capture the entire transit. The KELT telescope records images of huge swaths of night sky, so the scientists searched for slight, periodic dimming of any stars in the images. Once the slight variation in light was detected, they used other telescopes to determine exactly which star is affected and precisely how much it dims.
“Karen chased the planet down and got the data that we needed to ask for precious Keck time,” Scott Gaudi, associate professor of astronomy at Ohio State and member of the KELT team, said in a statement. “With the Keck data, we were able to take a much closer look and confirm the discovery of KELT-6b.”
“KELT-6b is a ℠metal-poor´ cousin of HD 209458b,” Keivan Stassun, professor of astronomy at Vanderbilt and member of the KELT team, said in a statement. “The role of metals in the stellar environments in which planets form is a major question in our understanding of these other worlds. This new planet is among the least endowed with such metals that we know of, and because it is so bright it should serve as a benchmark for comparative studies of how and under what conditions planets form.”
Thomas Beatty, a doctoral student at Ohio State, said the discovery of KELT-6b highlights the importance of partnerships involving low-power telescopes.
“KELT would be impossible without our network of professional and amateur observers,” he said in a statement. “They do a lot of the hard slogging in surveys like this one, staying up all night to watch stars that, more often than not, turn out not to have planets.”