|
|
-
Star gazing
Iowa State is home to the Whole Earth Telescope.
When he was just five years old, Steve Kawaler happened upon a Golden
Book of Astronomy in his home. That chance discovery spurred his lifelong
interest in the stars and planets.
"My older brother got caught up into the whole space thing during Sputnik,"
said Kawaler, professor of physics/astronomy. "He had all these books
laying around the house. Astronomy has been pretty much an obsession with
me every since."
That same Golden Book of Astronomy still occupies a prominent place
in Kawaler's Physics Hall office. But the Iowa State professor has come
a long way since his early foray into the subject.
These days Kawaler serves as the director of the Whole Earth Telescope (WET),
a worldwide network of 22 cooperating observatories that obtain uninterrupted
time-series measurements of variable stars. As the Earth rotates and the
object sets (or the sun rises), it comes into the field of view of another
WET observatory. The collaboration includes scientists from around the globe
in data acquisition, reduction, analysis, and theoretical interpretation.
For the first decade of its existence, WET was located at the University
of Texas in Austin. The operation moved to Iowa State and the physics and
astronomy department in 1997. Funding comes in part from the National Science
Foundation.
During a WET observation, scientists across the world will focus in on one
object with as many as 12 active sites participating. The operation is coordinated
from a single command center by electronic mail and long-distance telephone.
Data returned by e-mail from the various sites are reduced, combined and
subjected to preliminary analysis in real time to maximize the effective
use of the whole instrument. Following the run, the principal scientist
reduces all the data and drafts a preliminary manuscript, which is circulated
through the collaborators for that particular project.
"Basically the different sites across the globe will observe the same
area at different times," Kawaler said. "WET has the unique ability
to provide 24-hour monitoring of a single astronomical object."
WET observations are conducted twice a year for three weeks. But the benefits
to Iowa State, the physics and astronomy department and its students last
much longer according to Kawaler.
"Anytime we have a run, the campus receives numerous visitors from
the participating countries," he said. "We get to interact with
these scientists, an opportunity we wouldn't have if WET was headquartered
anywhere else.
"And since the data resulting from a WET run are stored on campus computers,
we get the first look," he continued. "To have that data at their
finger tips is extremely valuable for our graduate students and post-docs."
Two major projects have been completed with WET runs since the organization
came to Iowa State. Last year, the group trained their telescopes on a relatively
close pulsating white dwarf star, primarily made up of carbon and oxygen
in a crystallized state. Last November, a seismological analysis of an ancient
star gave the astronomers an idea of the physical condition deep within
the star itself.
"This is perhaps the largest collaboration of traditional astronomers
in the world," Kawaler said. "We have the opportunity to do topflight
science and establish topflight results.
"We're focused on a particular brand of science with a fairly focused
research area," he continued. "WET draws people together from
throughout the world to solve a problem."
Around LAS
September 11-17, 2000
|
|
