New images taken of an object five times the mass of Jupiter confirm that it is a giant planet closely orbiting a distant star, an international...
LOS ANGELES — New images taken of an object five times the mass of Jupiter confirm that it is a giant planet closely orbiting a distant star, an international team of astronomers reported.
The team of European and American astronomers said this is the first time a planet outside our solar system has been observed directly — a claim other scientists also have made.
The team first spotted the object last year as a faint, reddish speck of light circling a dim, brown dwarf — or failed star — 225 light-years from Earth near the constellation Hydra. Scientists at the time guessed the faint light was a planet, but said further observation was needed.
The discovery touched off a debate over whether the object was a planet or a background star. Scientists have discovered more than 130 of these so-called extrasolar planets by indirect means since the mid-1990s, but observing them directly has proved difficult.
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Refined images taken this year by the Very Large Telescope in northern Chile show two objects bound by gravity moving together, according to Gael Chauvin, an astronomer at the European Southern Observatory, who led the team.
Added Benjamin Zuckerman, an astronomer at the University of California, Los Angeles, who was part of the team: “I’m more than 99 percent confident.”
Chauvin’s team estimated the mass of the object, called 2M1207b, by measuring its brightness. They found that it was five times the mass of Jupiter and orbited a brown dwarf at a distance nearly twice as far as Neptune is from the sun.
Their observations will be published in a future issue of Astronomy and Astrophysics, the scientists said.
Lynne Hillenbrand, an assistant professor of astronomy at the California Institute of Technology, said the findings were intriguing, but cautioned against calling the object a planet.
“The claim of an object being a planet is subject to one’s definition of planet, and there are different camps on what that definition is,” Hillenbrand said.