"Celestial Discovery"

Five thousand light years away, spins a solar system that scientists believe is a smaller version of our own.

An international team of astronomers first observed two celestial bodies during a two-week period in 2006; now, they've determined that those bodies are planets that revolve around a star.

The "new" planets resemble smaller versions of Jupiter and Saturn; the star is smaller, dimmer, and colder than our sun.

The research is featured in the current edition of the journal Science; co-authors include Ohio State astronomy professors Scott Gaudi, Andrew Gould, Darren DePoy, and Richard Pogge and grad students Subo Dong and Stephan Frank. (Gould is a member of the Center for Cosmology and AstroParticle Physics, which is one of 10 high-impact Ohio State research programs that will receive $100 million in research funding in the next three years.)

Gaudi thinks these scaled-down versions of our solar system are very common.

The planets' discovery relied on gravitational microlensing, a technique that allows astronomers to find things that don't emit much light. When a massive dark object in space--like a planet, dim star, or black hole--crosses a star, the object's gravitational pull bends the light rays from the star and magnifies them like a lens. Astronomers can see the star get brighter as the lens crosses in front of it, and then fade as the lens gets farther away.

"We've hit our stride with this technique," Gaudi says.

Upcoming microlensing experiments--using telescopes on the ground and in space--will likely be able to detect planets like every one in our solar system except for Mercury, because it's so small.

The newly discovered planets' solar system matches up to ours in several ways.

The smaller planet is roughly twice as far from its star as the larger one, mirroring Saturn's distance from the sun compared to Jupiter's. And although the star is much dimmer than our sun, temperatures at both planets are likely to be similar to that of Jupiter and Saturn because of their proximity to the star.

“The temperatures are important because these dictate the amount of material that is available for planet formation,” Gaudi says. “Most theorists think that the biggest planet in our solar system formed at Jupiter's location because that is the closest to the sun that ice can form. Saturn is the next biggest because it is in the next location further away, where there is less primordial material available to form planets.”

“Theorists have wondered whether gas giants in other solar systems would form in the same way as ours did. This system seems to answer in the affirmative.”

(Read the full story from Ohio State Research News.)