The search for secrets of newborn stars

"You can track these over time" from Earth to study climate and weather changes on Mars, he says, adding wryly, "You could do this every day, except we have other things we want to do."

The observatory also is planning tests with two other submillimeter observatories that share the summit here with the SMA, the Caltech and James Clerk Maxwell observatories. The tests would link their larger, single dishes to the SMA's interferometer, improving the resolution of images by another 30 to 40 percent. It also would significantly increase the system's sensitivity to fainter signals, allowing the entire array to peer further back in time or observe more subtle details in nearby objects.

Another target for SMA will be a star known as CW Leonis, some 500 light-years away.

In 2001, a smaller, orbiting submillimeter telescope discovered that the star was entering its final stage as a red giant. The star is surrounded by large amounts of water vapor. This was the first time water - a necessary component for life - had been detected in a planetary system outside our solar system.

The team, led by Gary Melnick at the Harvard- Smithsonian Center for Astrophysics, speculated that the vapor might have come from several hundred billion comets that were furiously boiling away as the star expanded. But the satellite could only detect the water vapor and yield an estimate of its amount. The SMA team hopes to train its dishes on the star to see if it can help solve the riddle of the water's source.

Compared with its radio, optical, and infrared counterparts, submillimeter astronomy has been a relatively new kid on the block. Its between-the-cracks wavelengths were too low for infrared detectors to pick up but too high for existing radio detectors - at least until the 1970s, recalls Thomas Phillips, director of Caltech's submillimeter observatory.

At that point, Bell Labs and IBM were locked in a race to build smaller, faster computers using superconductors - devices that, when chilled sufficiently, conduct electricity with no resistance.

Dr. Phillips says he was working at Bell Labs at the time, and while the computer effort proved futile, the superconducting devices he developed looked to be just the ticket for detecting submillimeter radiation. Descendants of that device are now being used at the SMA and at the Atacama Large Millimeter Array (ALMA), a much larger millimeter and submillimeter interferometer still under construction in Chile's Atacama Desert.

Water vapor in the atmosphere blocks incoming submillimeter radiation, so astronomers have searched for places that are high and dry to build full-scale observatories.

By the late '80s, Mauna Kea became home to two facilities, which stand like sentinels at the entrance to Submillimeter Valley: the CalTech Observatory, with a 10.4-meter dish, and the Maxwell Observatory, with a 15-meter dish.

Over the next few years, Phillips continues, these facilities and an airborne observatory run by NASA made several discoveries that awakened the astronomy community to the range of discoveries the fledgling submillimeter field could achieve.

One of the most stunning, he says, was the discovery of a region of intense star formation where the Hubble Space Telecope's deep-field survey, conducted at optical and ultraviolet wavelengths, had showed only empty space. The results, published in the journal Nature in 1998, "woke everybody up," Phillips says.

Using the Maxwell submillimeter telescope, a team of astronomers led by David Hughes, with the University of Edinburgh's Institute for Astronomy, found regions of intense star formation at greater distances than those appearing in optical or ultraviolet telescope surveys.

The new data yielded rates of star formation at those distances - and at a younger period in the universe's history - some five times as high as the other surveys showed.

Until Dr. Hughes and his colleagues had trained the observatory's dish on that region of space, its secrets had been shrouded in thick clouds of dust and gas.

Another one of the research goals at SMA is to return to that region to tease out details the Maxwell telescope couldn't resolve.

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