(PLANETQUEST) -- Since the completion of its first phase in 2005, the Sloan Digital Sky Survey has been a boon to astronomers looking for a comprehensive map of the universe. University of Florida astronomer Jian Ge hopes that a new addition to the project, the Marvels interferometer, will bring a new feature to this map of the heavens - exoplanets.
"Current planet-finding instruments have a weakness in that they can watch stars one at a time," explained Ge, who leads the Marvels (Multi-object Apache Point Observatory Radial Velocity Exoplanet Large-area Survey) as part of the Sloan Digital Sky Survey III program in 2008-2014, which is funded in part by NASA. "Marvels will be able to monitor up to 120 objects at a time."
This increased capacity means that Marvels can be more efficient at watching stars for the telltale movements that indicate they have planets orbiting them. And because the project is slated to last 6 years, Marvels will be able to spot planets that are farther away and take much longer to orbit their stars than our planet does.
The instrument itself is an add-on to the SDSS telescope in Apache Point, New Mexico. Beams of light from the telescope will be fed to the Marvels instruments in a building some 40 feet away in order to get the stellar Doppler shift signals needed to find exoplanets. Marvels won't be sensitive enough to detect small, Earth-like planets, but it will give scientists clues of how many planets are out there, and which stars are worth a closer look for planets like our own. In addition, said Ge, "It will give us information to help understand planet formation and evolution, and planet-forming environments, as well as the properties of planet-hosting stars."
"Most exoplanet studies focus on stars of high-metallicity that are good candidates to have planets," said Ge. "Marvels is less biased, it focuses on a more homogenous sample - 11,000 stars over six years." This approach casts a wide net across the sky and will give astronomers a better overall idea of how common exoplanets are in our galaxy, especially around fainter stars. "Pessimistically, we expect to find 150-200 exoplanets," Ge explained.
Ge is also hopeful that the technology pioneered with the Marvels survey will help spark future efforts to find exoplanets. Already, his team has experimented with an infrared version of the Marvels interferometer, and Ge has plans to use the technology with the massive GTC 10.4 meter telescope (the world's largest) in the Canary Islands to confirm and follow up on targets, especially the Earth-like planets, found by NASA's Kepler mission, due to launch next year.
Ge is confident that Marvels will not only significantly increase the amount of known exoplanets, but also give astronomers a much more complete picture of our local universe. "We'll get a better overall idea with of what's out there because our survey is less biased," he said. "I think it will help us understand how rare our own system is and inspire the public about what's out there."
Written by Joshua Rodriguez/PlanetQuest
