Press Release

International Gemini Observatory celebrates success of new Canadian-built system

By SpaceRef Editor
June 2, 2003
Filed under , ,
International Gemini Observatory celebrates success of new Canadian-built system
gemini image

Today at the meeting of the
Canadian Astronomical Society (CASCA) in Waterloo, Ontario, the
seven-nation Gemini Observatory released one of the first images
captured using an innovative Canadian-built instrument commissioned
recently at its 8-metre Gemini North Telescope on Mauna Kea, Hawaii.
The new image reveals the core of the globular cluster M13, the
Hercules Star Cluster, in unprecedented detail. This stunning image can
be found at

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

The new instrument, the Altair adaptive optics system, captures three
(3) times more detail in infrared light than the Hubble Space Telescope
(HST) and will give astronomers a new capacity to see through the dust
that blocks optical light and look into the heart of star formations.
With this improved visibility, astronomers may soon be able to peek
into stellar nurseries, or watch the birth of galaxies that formed 10
billion years ago.

The Altair system, built in Victoria, British Columbia by the National
Research Council Canada (NRC) Herzberg Institute of Astrophysics
(NRC-HIA), corrects images to compensate for the distortion caused by
turbulence (mixing of warm and cold air) in the earth’s atmosphere.
Altair is seen as a significant improvement over other adaptive optics
systems and a major boost to the performance of the Gemini North
Telescope.

“This is a powerful demonstration of the instrumentation expertise in
Victoria,” said NRC President Dr. Arthur Carty, noting that the
achievement builds upon a long list of successes in innovative
technologies and Canadian contributions to the Gemini project. “We are
extremely proud of the work of NRC-HIA and its partners and join them
in celebrating this achievement today.”

Watching galaxies being born

One of the big questions facing the international astronomy community
today is how stars and galaxies form. While the Hubble Space Telescope
(HST) provides excellent high-resolution images, Gemini coupled with
Altair will be able to capture infrared images of fainter, hence more
distant, galaxies with three times the resolution. Astronomers also
need to study the spectra of distant galaxies to understand what is
happening within them.

The Gemini Observatory’s light gathering power (10 times that of the
HST) combined with the extra resolution provided by the Canadian-built
Altair, will allow Gemini’s infrared spectrographs to study the inner
workings of galaxies in depth.

“So now Hubble becomes our finding chart, and Gemini does the physics
on what Hubble sees,” says Dr. Matt Mountain, Director of the Gemini
Observatory. “For the very first time, we can look at gas swirling
around the nuclei of black holes. We can get our first glimpse of how
early mass assembled to form today’s galaxies.”

Another much-anticipated use of Altair is the search for planets
outside our solar system.

“Altair will give Canadian astronomers the potential to search for and
image a planet around a nearby star,” says Dr. Harvey B. Richer,
Canadian Gemini scientist and a professor at the University of British
Columbia’s (UBC) department of physics and astronomy. “A lot of people
have been waiting for Altair so they can do this.”

A first for Canada

NRC-HIA has a history of leadership in building instruments that
improve telescope performance. Recently, NRC-HIA scientists worked with
partners in the United Kingdom (U.K) to build the very successful GMOS
(Gemini Multi-Object Spectrograph) instruments that will allow both
Gemini Telescopes to obtain spectra of hundreds of objects
simultaneously, rather than one at a time. More than a decade ago,
working with partners in France, NRC-HIA staff developed a pioneering
adaptive optics system (PUEO) for the Canada-France-Hawaii Telescope
(CFHT), also on Mauna Kea.

But Altair represents the first time that the Canadian team at NRC-HIA
has built a complete adaptive optics system on its own. NRC-HIA did all
of the design and construction, the optics, mechanics, software,
electronics, and put them all together.

Altair produced its first high-resolution image only a few hours into
its first night on the telescope. “The fact that Altair worked right
out of the box is a significant technical achievement for the team,”
says Dr. Jean-Pierre Véran, Altair instrument scientist. “The simple
user interface we use to control Altair hides the extremely complex
software developed by our programming team”.

“Besides coordinating the motion of more than 20 motors, the software
also changes the shape of the active mirrors 1000 times a second, says
Jennifer Dunn, Lead Software Engineer. Spreading these functions over
multiple processors and making them work in unison was a real
challenge”

“We had strict limits as to the volume, centre of gravity and
interfaces,” says Dr. David Crampton, leader of the NRC-HIA Advanced
Technology Research Group in Victoria. “This is a high-precision
instrument, we worry about things flexing by microns – a thousandth of a
millimetre.”

Overcoming these challenges required a talented multidisciplinary team
that understood the needs of scientists, something for which NRC-HIA is
well known.

“NRC-HIA is a very innovative group and it has been a great partner in
the Gemini endeavour,” says Mountain. “They’re very good at bringing
together astronomers and engineers to design products that deliver
great science. It’s that partnership between science and technology
that brings excellent results.”

The next step in adaptive optics

Canada’s Altair improves on previous adaptive optics systems in several
ways. First, the area of the sky that is sharpened will be larger than
before. This is possible because Altair corrects high-altitude
turbulence – approximately 6.5 kilometres above the telescope. Studies
have shown that most of the atmospheric turbulence above Mauna Kea is
at this altitude. By focusing on the area of greatest turbulence,
Altair can correct the image for a larger area of the sky.

Second, Altair captures more light than previous systems. “It transmits
about 90 per cent of the infrared light, which is much higher than any
other adaptive optics system,” says Glen Herriot, Altair project
manager. “This makes the sensitivity for astronomical objects much
higher.”

Third, Altair is easier to use than earlier systems, which often
require a team of experts to run. Astronomers will be able to view more
objects each night, and concentrate on what they’re seeing rather than
how to use the equipment. “It really is a one-button instrument, that
adjusts itself for changing weather conditions,” says Herriot.

In addition, Altair can feed the corrected images to one of several
instruments available on Gemini North, which expands the range of
scientific problems that can be investigated.

“Altair makes corrected light available to the entire community of
astronomers,” says Mountain.

About Gemini

The Gemini Observatory consists of twin state-of-the-art 8-metre
telescopes that are located in each hemisphere in order to provide
complete sky coverage. The Gemini North Telescope is located on
Hawaii’s Mauna Kea, and Gemini South is located on a mountain in the
Chilean Andes.

The Gemini partnership consists of the United States, United Kingdom,
Canada, Australia, Argentina, Brazil and Chile. Astronomers from each
partner country can apply for time on Gemini regardless of
institutional affiliation and time is awarded in direct proportion to
each country’s contribution to the partnership.

Background information:

More information on how Altair works can be found at:
http://www.hia-iha.nrc-cnrc.gc.ca/media/2003-06-02a_e.html

SpaceRef staff editor.