Cosmic Peephole Leaves Astronomers Agog
SAN ANTONIO — FOR American astronomers, long-held dreams are coming true - while a potential nightmare surfaces.
The Hubble Space Telescope is providing the most detailed views of the universe ever seen by man. This week, scientists revealed that by peering deep into one tiny patch of the cosmos, they had discovered 1,500 to 2,000 galaxies.
The clearer views of distant, unusually shaped clumps of stars is expected to help unlock the mysteries of how and when the universe was created. Astronomers also saw the face of star - other than our own - for the first time.
The historic breakthroughs were reported here at a meeting of the American Astronomical Society. But the excitement was tempered by more earthly concerns.
Neal Lane, director of the National Science Foundation (NSF), warned astronomers that the recent government shutdowns created an ''unprecedented, abominable mess'' that will likely disrupt their funding.
Dr. Lane explained that it will take six to nine months or longer to work through the paperwork logjam that built up during a month of enforced NSF inactivity. He said even the ''heroic'' efforts now being made by ''our dedicated but terribly demoralized staff'' may not prevent funding gaps for ongoing research programs. He added that there also ''are likely to be ... substantial delays in funding new awards.''
That's not a welcome message for astronomers. While the research was done with the Hubble telescope, funded by the National Aeronautics and Space Administration (NASA), much of the follow-up research will be done on the ground. NSF is the main funding agency for US ground-based astronomy.
When put into orbit above the earth, the Hubble telescope's main mirror was discovered to be flawed. But fitted with corrective lenses, the telescope ''has such superb optics'' that it ''has given us an unprecedented view'' of a detailed portion of the sky, said Robert Williams, director of the Space Telescope Science Institute in Baltimore.
For 10 days, the Hubble eye was pointed at a speck of sky only as large as a grain of sand held at arm's length. But that spot near the North Star shows a plenitude of galaxies of different shapes, colors, sizes, and brightnesses. Some of the images are of objects a hundred times fainter than the most powerful ground-based telescope can see under the best viewing conditions.
''One of the great legacies of the Hubble telescope will be these deep images of the sky showing galaxies to the faintest possible limits [of seeing] with the greatest possible clarity, from here out to the very horizon of the universe,'' Dr. Williams said. Astronomers hope that, by studying galaxies at great distances, they will see them when they were young because it will have taken many billions of years for the galaxies' light to reach Earth. By seeing galaxies at different ages back to a time when the universe itself was relatively young, astronomers hope to learn how galaxies form and develop.
But to do that they need help from ground-based observers. Williams noted that, while he thinks many of the galaxies are indeed quite distant, this will not be known with certainty until their distances are determined. Ground-based telescopes are better equipped to make the kind of measurements needed to pin down distances. Thus, for those galaxies in the Hubble survey that are bright enough for ground-based viewing, distances can be obtained relatively quickly.
Meanwhile, with a display of enthusiasm to match that of the galaxy survey team, Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., presented the first-ever image of the surface of a star other than the sun. It is the red giant Betelgeuse, which now shines brightly in the Northern Hemisphere sky in the constellation Orion.
What Dr. Dupree and her partner Ronald Gilliland of the Space Telescope Science Institute found was a ''total surprise,'' Dupree said. Instead of lots of dark, relatively cool sunspot-like markings, they found a single, large area brighter and hotter than its surroundings. It is some 2,000 Kelvin (roughly 2,000 degrees C) hotter than its 5,000 Kelvin surroundings. It will take more observations and much rethinking of stellar theory to figure out what is going on, Dupree said.