NSF PR 00-75 - October 16, 2000
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Gemini Cuts Deep into Galactic Core with Release of
The first scientific observations from the Gemini North
telescope provide a dramatic glimpse into the elusive
core of the Milky Way, including an intriguing bow-shock
from a star as it plows into a poorly understood gas
cloud a mere three light-years from the galactic center.
Long-suspected of harboring a huge black hole, the
center of the Milky Way is a beehive of activity,
with hapless stars flung around the core at tremendous
"There has a been a buzz of increased interest by astronomers
lately in looking at the properties of the core,"
says UCLA Astronomer Dr. Andrea Ghez, whose work over
several years at the W.M. Keck Observatory is responsible
for pinpointing the exact location of the central
black hole. "With this excellent science quality data,
Gemini has demonstrated its many unique capabilities
for studying our galaxy and beyond. It is a remarkable
new tool in our toolbox for exploring the universe."
The Gemini Observatory is managed by the Association
of Universities for Research in Astronomy, Inc. (AURA)
under a cooperative agreement with the National Science
Foundation (NSF). The NSF also serves as the executive
agency for the international partnership.
The object, known by the unglamorous name of IRS8,
was only an ill-defined smudge until Gemini came along.
Now, the Gemini telescope's advanced optics show that
IRS8 appears to be a star that is plowing through
a poorly understood gas and dust cloud near the galactic
center. Moving relative to the cloud, the star creates
a very obvious bow-shock wave, similar to the wave
that forms in front of a boat as it goes through water.
This finding could alter scientists' understanding
of the center of our galaxy once astronomers determine
how the star and gas cloud are moving relative to
each other. By studying this interaction, the properties
of the gas cloud and the conditions surrounding the
star will be better understood and provide a valuable
new tool for probing the intense conditions near the
center of our galaxy.
The image released today represents only a fraction
of the total data available to scientists from this
study. "Never before have we seen such a large area
of the galactic center this clearly," said Dr. François
Rigaut of the Gemini Observatory who led the project.
"The data is also being released to scientists worldwide
regardless of affiliation so that astronomers can
make the most of this data as quickly as possible."
However, it will still take some time before astronomers
will be able to dig out all of the treasures buried
in this initial digital gold mine of data. "This is
the first scientific data to be released to the astronomical
community by the Gemini Observatory," says Director
Dr. Matt Mountain, "and to be able to release such
a spectacular image and data set shows the tremendous
potential of these telescopes."
The data was taken at several infrared wavelengths
and combined to create a "color" image. The remarkable
sharpness of the image is due to a technology called
adaptive optics that actually corrects for distortions
to starlight caused by turbulence in the Earth's atmosphere.
The adaptive optics instrument used is called Hokupa'a
and was built by the University of Hawaii, Institute
for Astronomy and funded through an NSF grant.
Observing the galactic center is especially difficult
because its light must travel through thousands of
light-years of gas and dust before we can see it from
our perch in the galactic suburbs. Only a small portion
of the light ever makes it to our planet and most
of that is in the infrared (or heat) part of the spectrum.
The Gemini Observatory has been designed to make the
most of the trickle of infrared radiation from space
by using sophisticated new technologies like adaptive
optics and infrared optimization that capitalize on
the ideal infrared conditions at Mauna Kea.
The data was obtained over several nights in July and
August as part of a preliminary science testing period
as the Gemini North telescope nears completion on
Mauna Kea in Hawaii.
The Gemini 8-meter Observatory Project is a multi-national
collaboration that will provide two nearly identical
eight-meter telescopes to an international community
of astronomers. Both telescopes will incorporate new
technologies that allow large, relatively thin mirrors
to collect and focus both optical and infrared radiation
from space -- at times with even more clarity than
is possible with the Hubble Space Telescope. The telescopes
are located on Hawaii's Mauna Kea (Gemini North) and
the other on Cerro Pachón in central Chile (Gemini
South), and hence will provide full sky coverage.
Gemini North is nearing full scientific operations
early in the year 2001 and Gemini South will follow
about six months later.
The Gemini Observatory provides the astronomical communities
in each of seven partner countries with state-of-the-art
astronomical facilities that will allocate observing
time in proportion to each country's contribution.
In addition to financial support, each country also
contributes significant scientific and technical resources.
Other research agencies that form the Gemini partnership
include: the UK Particle Physics and Astronomy Research
Council (PPARC), the Canadian National Research Council
(NRC), the Chilean Comisión Nacional de Investigación
Cientifica y Tecnológica (CONICYT), the Australian
Research Council (ARC), the Argentinean Consejo Nacional
de Investigaciones Científicas y Técnicas
(CONICET) and the Brazilian Conselho Nacional de Pesquisas
Cientificas e Tecnológicas (CNPq).
images, see: http://www.gemini.edu/galactic.html
on adaptive optics see: http://www.gemini.edu/public/adaptive.html
Television editors: B-roll footage is available
from Dena Headlee at NSF(703)292-8070.