Tags:
Journalism of Courage
A huge planet which scientists believed to be orbiting around a distant star has been shown to be an optical illusion — a discovery which could take several more ‘‘planets’’ off the list of worlds beyond our solar system, researchers said on Wednesday.
Astronomer Gregory Henry of Tennessee State University said his analysis revealed that the ‘‘planet’’ — one of several far-flung discoveries announced with great fanfare two years ago — was actually a trick of light created by giant ‘‘star spots’’ on its sun’s surface.
‘‘The existence of this planet was certainly an illusion,’’ Henry said in an interview. ‘‘It is easy to be fooled.’’
Teams of astronomers have thus far identified some 101 so-called ‘‘extrasolar’’ planets, with each discovery fuelling hopes that one day humans may be able to locate far-off worlds capable of supporting life.
But Henry said his new analysis, published in the current edition of the Astrophysical Journal, showed a small number of them could simply be optical tricks. Henry and his colleagues took a new look at the star identified as HD 192263, which both California and Swiss researchers said in 1999 had large, gaseous Jupiter-like planet swinging around it in a tight orbit.
The astronomers did not see the actual planet around the star, which lies some 63 light years from Earth. But they reached their conclusion by detecting a tell-tale ‘‘wobble’’ in the star which would indicate the gravitational pull exerted by an orbiting planet.
Henry and his team took a closer look at that “wobble” and concluded that it was in fact caused by the passage of large dark ‘‘star spots’’ across the star’s surface — creating a light signature similar to that of an orbiting planet.
When they determined that the star spot moved across the star at precisely the interval attributed to the supposed planet, they knew they had disproved the theory, he said.
