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The news stories described a brief article -- it took up just two pages -- in the Feb. 27 issue of Nature. The article, written by University of Western Ontario astronomer David Gray, was graced with the boring title "Absence of a planetary signature in the spectra of the star 51 Pegasi."
But a piece of commentary in the front of that same issue of Nature grabbed the attention of journalists and astronomers with this headline: "One of our planets is missing."
In his Nature article, Gray said that he, just like the Swiss astronomers Mayor and Queloz, and just like Butler and Marcy, had looked at spectral lines created by light from 51 Pegasi through his own telescope in Ontario.
Gray used a different method of measuring changes in the spectrums of light from the star. Using that method, Gray said, he detected the telltale sign of a star that is swelling and then contracting, rather than moving back and forth under the influence of planetary gravity. In other words, Gray maintained, the star was vibrating to the rhythm of its own nuclear fires.
Marcy and Butler were quick to respond, drafting a one-page paper calling the Ontario scientist's assertions nonsense. The paper, posted to their Website, contends that Gray's theory proposes an impossible sort of star -- one that would shrink to half its size, then swell back again to original volume, every four days or so.
For Gray, however, the San Francisco astronomers' rush to rebut merely betrayed how jealously they guard their coterie of planets.
"If one gets emotionally attached to a particular hypothesis, one is going to get upset," Gray says.
Gray wasn't the last scientist to lance at the theory of planets in outer space. As has been the case with scientific discoveries through the ages, challenges are beginning to mount. The resulting zone of doubt has been at least as cruel to the challengers as the challenged.
Attack of the Binary Stars
Xiaopei Pan, a polite man in slacks, a white shirt, and black canvas slip-on shoes, gestures at the left wall of his small office in the basement of the astronomy building on the campus of the California Institute of Technology in Pasadena. On that wall are copies of papers he has written, a citation he received in a book about U.S.-funded astronomical research, graphs describing stars he has observed.
They're mementos of a 17-year sojourn that led from life as a government scientist in the People's Republic of China to the vanguard of U.S. astrophysical research.
Now, like Butler and Marcy, Pan sits in an extremely uncomfortable zone of uncertainty.
He wishes to publish a scientific paper that would, if true, erase at least two of the newly discovered extrasolar planets: 51 Pegasi, the first ever discovered, and tau Bootis, a similar system, found by Butler and Marcy, that appears during the summer to observers in the Northern Hemisphere. But to publish, he will have to defy his department, other members of his research team, and the customs of U.S. science.
His anguish is palpable.
"We're all looking for the truth," Pan says. "This research is funded by taxpayers. We're supposed to tell taxpayers the truth."
Pan left his job as a Chinese government astronomer 17 years ago for a stint as a visiting scientist at the U.S. Naval Observatory and the freedom of Western-style science.
A scientific prodigy, Pan achieved a high position as a mainland China government scientist after graduating from the department of astronomy at Nadjing University in 1967, and later receiving his doctorate from Academy Sinica in Taiwan.
But he was intrigued by the careers of the Western scientists he met when he traveled to conferences -- the raucous hubbub of competing theories, the state-of-the-art research on multimillion-dollar instruments. In 1980, he was courted by the U.S. Naval Observatory and took a two-year appointment as a visiting scientist there. When offered an appointment at the Harvard-Smithsonian Center for Astrophysics in 1987, he grabbed it. And when Harvard scientists Mike Shao and Mark Colavita jumped to the West Coast to work on the next generation of interferometers -- arrays of individual telescopes whose images are combined -- Pan followed suit.
He would be joining an astronomical dream team that would operate in dream conditions. Working on Mount Palomar outside Los Angeles, in partnership with NASA's Jet Propulsion Laboratory, these scientists would develop the most advanced instrument of its kind. Under the direction of Caltech Professor Shri Kulkarni, Shao and Colavita would perfect the NASA interferometer, which delicately combines the light from several telescopes in order to detect objects no other instrument has. Pan would conduct astrophysical research on the instrument.
If all went as planned, the Caltech-JPL team would eventually move from Mount Palomar to Hawaii, where the researchers would turn the Keck astronomical observatory's apartment-size, 10-meter telescopes into a pair of combined-image binoculars. Thereafter, the team would spearhead NASA plans to send a binocular telescope into space at a cost some say could reach $10 billion.
The mission of this NASA-funded research program was almost Star Trekian in its ambitions: These men were to find planets -- and perhaps, the conditions for life -- in star systems far from our own.
But the dream team has faltered in its trajectory because Xiaopei Pan's research went where no NASA-funded scientists had gone before: The results, he believes, show that in at least some cases, Butler and Marcy have been wrong, and found planets when they should have found stars.
Other members of Pan's team disagree. Shri Kulkarni, the leader of Pan's research team, says Pan based his conclusions on observations made before the Mount Palomar interferometer was perfected, and before the team could make reliable scientific interpretations based on its data. Shao and Colavita say the same thing.
"If you want to go out on a limb, you could say it is resolved -- which wouldn't be wise," says Kulkarni of Pan's assertion. "It takes a couple of years to debug these systems. Most of us in the group don't think we can say anything about whether 51 Pegasi has a companion star."
