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Gemini Observatory
Hilo, Hawai`i

Media Contacts:
Peter Michaud
Gemini Observatory, Hilo, Hawai`i
Phone: 808/974-2510
E-mail: pmichaud{at}gemini.edu

Jennifer Akingkubedaggs
Gemini Observatory, Hilo, Hawai`i
Phone: 808/974-2607
E-mail: jaking{at}gemini.edu

FOR RELEASE: June 2, 2003

New Gemini Images Exemplify the Power of Adaptive Optics

Part 1 of 2

A razor-sharp image was released today revealing new details at the
heart of a famous star cluster. The thousands of swarming stars at
the cluster's core were made visible by an innovative adaptive optics
system called Altair that is currently being commissioned on the
Frederick C. Gillett Gemini Telescope on Mauna Kea, Hawai`i.

Among several of the first images from Altair (Altitude Conjugate
Adaptive Optics for Infrared), the high-resolution data reveal
multitudes of stars with stunning clarity. The dense star cluster
known to generations of skywatchers as the Great Hercules Cluster or
M-13 is home to hundreds of thousands of stars that, in the center,
are often blurred by our atmosphere into a great glowing mass. "The
resolution obtained in these images is approximately equivalent to
seeing the separation between an automobile's headlights on the
Golden Gate Bridge in San Francisco while standing 3,850 kilometers
away in Hawai`i," said Observatory Adaptive Optics Scientist Dr.
Francois Rigaut. 

The close-up images of M-13, with and without Altair, as well as a
spectacular reference image of the entire cluster, provided by the
Canada-France-Hawaii Telescope, can be viewed and downloaded at:

      http://www.gemini.edu/media/images_2003-2.html

The remarkable detail in the Gemini images was made possible by
Altair's unique ability to correct starlight that has been blurred by
atmospheric turbulence using adaptive optics with altitude
conjugation.

Most adaptive optics systems that are currently in use correct for
distortions to starlight by assuming that all of the distortions
occur where starlight is collected -- near the surface of the
telescope's primary mirror. In an altitude-conjugated system like
Gemini's, the distortions are assumed to be at the dominant
turbulence layer of the atmosphere. By conjugating or tuning the
system for a specific layer above the telescope, Altair can generate
a more accurate model of the starlight's path through our atmosphere.

"Adaptive optics with altitude conjugation is a pioneering new
technique that is a powerful way to measure and fix distortions to
starlight, which traveled undisturbed for vast distances through
space until hitting pockets of warm and cold air in earth's
atmosphere," said Glen Herriot, the systems engineer who managed the
building of Altair in Victoria, BC at the laboratories of the
National Research Council of Canada. Altair is able to precisely
correct the distorted starlight up to 1,000 times per second using a
sophisticated, deformable mirror about the size of the palm of your
hand. "The end result is," says Herriot, "images that rival or even
exceed the sharpness of pictures taken from space."

Working with Gemini Observatory personnel, the Canadian team headed
by Project Manager Herriot and Project Scientist Dr. Jean-Pierre
Veran, have been commissioning Altair on Gemini North from late 2002
through early 2003. The instrument team, comprised of 25 scientists
and engineers, guided the Gemini adaptive optics system from design
to commissioning over the past six years. "Commissioning a precision
instrument on a 7-story, 350-ton, sophisticated telescope is
especially challenging because of the extremely intricate
coordination required to make all the systems work together
seamlessly," said Herriot. Altair's commissioning on Gemini is
expected to be complete before the end of 2003.

A key feature of Altair's sophistication is the ability to
automatically monitor, adjust and optimize multiple parameters during
image exposures. The idea is to make adaptive optics user-friendly
for our community. When atmospheric conditions allow, simply point
and click and near diffraction-limited images are delivered to a
camera or spectrograph. Altair continually measures and reports on
the images' level of detail making it one of the most efficient
adaptive optics systems in the world. "By routinely delivering
infrared images much sharper than is currently possible even from
space, Altair gives observers a tremendous advantage in probing
deeper in the universe and making more accurate measurements of
astronomical objects," Dr. Veran says.

"Altair enormously enhances the quality and power of our imaging and 
spectroscopy," says Dr. Matt Mountain, Gemini's Director. "Gemini
will soon deliver diffraction-limited images in the near-infrared."
Gemini's theoretical diffraction limit (maximum resolution) is about
40 milli-arcseconds in the near-infrared H-band (1.6 micrometers
wavelength). At this point in commissioning, Altair can deliver
60-milli-arcsecond resolution in the H-band (60 milli-arcseconds is
comparable to viewing one grain of sand from about 1.6 kilometers or
1 mile away). 

Dr. Mountain pointed out that Altair's commissioning means that one
of the most sophisticated adaptive optics system in the world is now
built-in to Gemini North as a facility instrument, and will soon be
routinely available to all scientists throughout the Gemini
partnership. 

"This is a major achievement towards our Gemini goal of delivering
space-quality images from an 8-meter, ground-based telescope," said
Dr. Mountain. 

Gemini's Associate Director Dr. Jean-René Roy explains that Altair is
a major step forward in Gemini's aggressive plans to maximize the
potential of adaptive optics on ground-based astronomical imaging.
Dr. Roy elaborates, "Altair, representing the foundation of
tomorrow's adaptive optics technology, is important for the success
of the next generation of 30- to 100-meter, diffraction-limited,
infrared, ground-based telescopes now on the drawing boards." 

Future generations of adaptive optics technologies like these will
undoubtedly revolutionize ground-based astronomy. For now, Altair is
state of the art and provides a powerful new eye on the universe.

For more information, see the Adaptive Optics background information,
http://www.gemini.edu/project/announcements/press/
pr2003-2_background.html

 - Continued -

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