Reaching for the Stars
BUILDING HIGH-QUALITY INSTRUMENTS AND USING THEM TO MAKE DRAMATIC DISCOVERIES HAS PUT UF'S ASTRONOMY DEPARTMENT ON THE INTERNATIONAL STAR CHART
Florida is not exactly prime telescope country. The international
observatory at Mauna Kea, Hawaii, is 13,800 feet above sea level. The observatory
at Cerro Tololo, Chile, is 7,000 feet above sea level. Florida's highest
point is 345 feet above sea level.
UF's Rosemary Hill Observatory has a telescope whose primary mirror is 30 inches in diameter. Mauna Kea's Keck II telescope is more than 30 feet in diameter.
So when a team of astronomers from the University of Florida made international news last March with their discovery of a solar system forming 220 light years from Earth, their accomplishment was made even more impressive by the route they took to achieve it.
Stan Dermott knew he was getting a "fixer upper" when he took over as chair of UF's astronomy department five years ago. While the department had done admirable work with limited resources over the years, faculty members were hampered from making significant contributions because UF didn't have a big telescope and it didn't have the connections to get research time on a big telescope.
But Willard Harrison, dean of UF's College of Liberal Arts and Sciences, was committed to the astronomy department, and he backed up his commitment with resources.
Harrison says the "gee whiz" factor played an important role in the decision to promote astronomy.
"New worlds, new stars, new planets," Harrison says. "There's just this intrinsic reaction for people that says, `This is exciting stuff.'"
Dermott knew the chances of UF securing the millions of dollars necessary to become a partner in a major telescope were slim, so instead he sought out someone with access to existing telescopes.
He found that person in Charles Telesco, a respected astronomer at NASA's Marshall Space Flight Center. After 15 years of ground-breaking research at NASA, Telesco relished the opportunity Dermott presented him to help advance UF's astronomy research.
"My long-term goal was to build a research program. That's why I came here," Telesco says. "Stan wanted to build the department, and he thought I could help with that."
Telesco's already solid reputation observing objects outside our galaxy immediately began to pay off for the university. Between 1993-94 and 1997-98, the astronomy department's annual budget grew from $492,132 to more than $2.1 million, with most of that increase coming from foundations and federal agencies like NASA and the National Science Foundation (NSF).
But it was Telesco's skill engineering cameras for the relatively new field of infrared astronomy that offered UF a shortcut to the astronomy big time.
"We haven't got a big telescope in Florida, and we never will," Dermott says. So the UF astronomers developed a plan to make themselves indispensable to the scientists and institutions that do have telescopes.
"By concentrating on the instruments, we can be just as effective," Dermott continues. "But it's a very hard path to go -- it's very competitive. We have to prove we have the best instruments in the world."
If the international acclaim for their research findings and the multi-million-dollar contracts to build instruments for the next generation of telescopes are any measure, the astronomy community is convinced.
UF's current workhorse instrument is OSCIR, the Observatory Spectrometer Camera for the Infrared. Telesco began developing OSCIR in 1992 while he was still at the Marshall Space Flight Center in Huntsville, Alabama. Since coming to UF, Telesco has dramatically upgraded OSCIR's electronics.
Telesco humbly refers to the microwave oven-sized device and the giant telescopes it is attached to as "just a camera with a very large lens."
Infrared starlight striking a telescope's giant curved mirror is focused onto OSCIR's centimeter- square, $50,000 silicon brain. More than 16,000 pixels on the silicon chip assign a brightness value for the infrared energy striking each of them, and OSCIR converts those values into a graphic representation of the original image.
OSCIR does its job so well that earlier this year an international consortium awarded Telesco and his team a $1 million contract to build an even-more- sensitive camera for the Gemini telescope program. Gemini North at Mauna Kea and Gemini South, atop Cerro Pachon in Chile -- a stone's throw from Cerro Tololo -- will be two of the most advanced 8-meter telescopes in the world. Argentina, Australia, Brazil, Canada, Chile, the United Kingdom and the United States are collaborating on the project.
The Gemini project is particularly well suited for Telesco's infrared imagers because the telescopes are being designed to emit much less of their own interfering infrared "noise," says Todd Boroson, U.S. director for the Gemini program. This will enable the mid-infrared instruments to "see" much fainter, more distant objects.
The new camera being developed at UF will have about 65,000 pixels on a chip about 1.5 times larger than OSCIR's, giving astronomers an even clearer view of the heavens.
"Less than five years ago, Charlie's first infrared detector had a resolution of only 20 pixels," UF doctoral student Scott Fisher says. "So the Gemini detector will be more than 3,000 times more sensitive. Combine that with the quality of the Gemini telescopes and we're going to be able to see some amazing things."
UF's selection as the instrument-builder for Gemini meant a huge boost in prestige.
"It is very significant since they were selected by a committee of top scientists who work in this field," Boroson says. "The UF team is certainly one of the best teams who design, build and use this sort of instrumentation."
OSCIR also was the key to Telesco's team sighting the budding solar system.
The star the scientists scoped out bears the decidedly no-nonsense name HR4796A. Its companion, HR4796B, is about 47 billion miles away from it but has no dust disk. The pair is about 220 light years from Earth, in the constellation Centaurus, visible primarily from the Southern hemisphere.
HR4796A could represent what our solar system looked like in its infancy, almost 5 billion years ago, when the Sun was 10 million years old and Jupiter and Saturn were forming, Telesco says. The HR4796 pair is estimated to be about 10 million years old, which puts the dust disk precisely in the proper planet-building time frame.
Fisher, who was working the telescope control panel the night of the discovery, says: "This may be the primordial dust that planets form from. These are the conditions that would have to be met for planets to form."
If the entire dust disk has formed planets or is forming them, the solar system would measure more than three times the distance from our Sun to Pluto. However, Telesco says, planets may be forming only near the inside edge of the disk, an area about the size of our solar system.
Increased funding and international recognition have helped UF's astronomy department build on its current success by enabling it to compete for top faculty and graduate students.
"Now, when we advertise for faculty we get really good candidates," Dermott says. "When you think of schools like Harvard, Princeton -- these are people who want to come here now."
Elizabeth Lada and Richard Elston are two examples.
Lada from the University of Maryland and Elston from the Cerro Tololo Inter-American Observatory have each won major research grants since coming to UF.
Elston is widely regarded as one of the best young builders of near-infrared instrumentation for large telescopes. With support from the NSF, he is developing the first fully cryogenic, near-IR, multi-object spectrometer.
This device will allow astronomers to obtain infrared spectra of between 50 and 100 astronomical objects simultaneously, allowing them to carry out projects in a single night that would have taken between 50 and 100 nights with existing instruments. Such a dramatic increase in the number of objects that can be observed in a single night will allow astronomers to study entire classes of objects rather than just one or two hopefully representative ones.
Lada has established herself as a leader in the field of star formation research. In particular, her work on the global star- forming properties of giant molecular clouds has had a major impact on the field. These clouds are believed to be the sites of all star and planet formation currently taking place in our galaxy.
Using newly developed infrared array cameras that can penetrate obscuring veils of dust in these clouds and reveal buried young stellar objects, Lada discovered that most stars, even those like our own Sun, are born in young rich clusters, embedded deeply in the gas and dust within these clouds. This result has been cited by a leading scientist as being "one of the three most important results in observational star formation in the last decade."
UF also has become a destination for some of the world's brightest students.
Mark Wyatt is one of them. The 25-year-old doctoral student from England studied at Cambridge as an undergraduate and at the University of London for his master's degree. His faculty adviser told him the UF astronomy department was an up-and-coming one, and now he studies solar-system dynamics with Dermott.
"It's good to come to a department that's growing with good people," he says.
Likewise for Lauren Jones, who came to UF in 1995 from the University of Alabama and previously spent two years studying astronomy at Moscow State University in Russia. Telesco was her main draw to UF, she says, and while she now studies near-infrared astronomy with Elston, she says she's as glad as ever to be here. Like several other UF astronomy graduate students, she has a NASA fellowship.
"I think the main thing that's kept me here is that the atmosphere (in the graduate program) is better than anything I've ever seen," says Jones, 29. "There are a lot of young faculty who want to see the program grow."
As spectacular as the past few years have been for UF's astronomy department, the future may hold even more excitement.
Infrared astronomy is a relatively young field, having emerged only in the late 1960s, so the list of objects infrared astronomers have yet to explore is a long one. That leaves teams such as UF's an enormous expanse of virgin territory.
Because infrared astronomy is able to penetrate dust disks such as the one surrounding HR4796A, it is the most likely field to uncover the secrets of how planets are born.
"The University of Florida's decision to form a group specializing in infrared astronomy, and especially infrared detection instruments, I think puts them right at the forefront of the kind of research that will be important during the next few years," says Hugh Van Horn, director of the division of astronomical sciences at the NSF.
That's just where they like it.
Stanley Dermott
Professor and Chair, Department of Astronomy, (352) 392-2052, dermott@astro.ufl.edu
Charles Telesco
Professor, Department of Astronomy, (352) 392-4455, telesco@astro.ufl.edu
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