Washington, Jan 6 (Inditop.com) Ten percent of solar systems in the whole universe are like ours, says an astronomy study.
“Now we know our place in the universe,” said Ohio State University (OSU) astronomer Scott Gaudi. “Solar systems like our own are not rare, but we’re not in the majority, either.”
The finding comes from a worldwide collaboration headquartered at Ohio State called the Microlensing Follow-Up Network (MicroFUN), which searches the sky for extrasolar planets.
MicroFUN astronomers use a method called gravitational microlensing, which occurs when one star happens to cross in front of another as seen from Earth.
The nearer star magnifies the light from the more distant star like a lens. If planets are orbiting the lens star, they boost the magnification briefly as they pass by.
This method is especially good at detecting giant planets in the outer reaches of solar systems — planets analogous to our own Jupiter.
This latest MicroFUN result is the culmination of 10 years work — and one sudden epiphany, explained Gaudi and Andrew Gould, professor of astronomy at Ohio State.
Ten years ago, Gaudi wrote his doctoral thesis on a method for calculating the likelihood that extrasolar planets exist. At the time, he concluded that less than 45 percent of stars could harbour a configuration similar to our own solar system.
Then, in December of 2009, Gould was examining a newly discovered planet with Cheongho Han from the Institute for Astrophysics at Chungbuk National University in Korea. The two were reviewing the range of properties among extrasolar planets discovered so far, when Gould saw a pattern.
“Basically, I realised that the answer was in Scott’s thesis from 10 years ago,” Gould said.
The find boils down to a statistical analysis: in the last four years, the MicroFUN survey has discovered only one solar system like our own — a system with two gas giants resembling Jupiter and Saturn, which astronomers discovered in 2006 and reported in the journal Science in 2008, said an OSU release.
“With billions of stars out there, even narrowing the odds to 10 percent leaves a few hundred million systems that might be like ours,” he said.
Gaudi presented these results at the American Astronomical Society Meeting in Washington DC.
