By Anna Pulley
By Erin Sherbert
By Chris Roberts
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By Rachel Swan
By Joe Eskenazi
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By Erin Sherbert
Butler and Marcy hit pay dirt at 8:30 a.m. on Jan. 17, 1996, at the annual meeting of the American Astronomical Society at San Antonio's El Palacio del Rio hotel. The society had arranged a press conference to present papers from the conference. Marcy dropped a bombshell, announcing two newly discovered planets. One was found orbiting the star 70 Virginis in the constellation Virgo; the other circled 47 Ursae Majoris, in the Big Dipper.
Weeks before, Swiss astronomers Michel Mayor and Didier Queloz had announced they had used similar techniques to detect a planet orbiting 51 Pegasi, in the constellation Pegasus. Marcy and Butler had also been observing 51 Pegasi, and they warmed the audience up in San Antonio by announcing they had confirmed the Swiss astronomers' results. But the response to the San Antonio announcement was bedlam, just the same. One of the Marcy-Butler planets appeared to be temperate enough for liquid water to exist there -- in other words, the life zone was present somewhere else in the universe.
"Bring your fishing rods, because there's water," Nature Astronomy Editor Leslie Sage recalls Marcy saying.
After a decade in the cold, after 10 years in featureless office cubicles, cramped observing rooms, and neon-lit college chemistry labs, Marcy and Butler were invited into the warmth of mainstream astronomy. And they became really, really famous.
Marcy and Butler have a Web page called Planet Search. Linked to it is Butler's electronic resume, which mentions 48 newspaper, magazine, and television stories under the heading "Selected Recent Media Coverage & Public Outreach." The articles indeed represent a small sampling of the hundreds of articles published around the time of their San Antonio announcement.
The Gray Letter
Not mentioned on Butler's curriculum vitae are the dozen or so articles in publications such as New Scientist, Astronomy, and Scientific American spawned by an event remembered in astronomical circles as "The Gray Letter."
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.