Scientists See Better, Fainter with New Keck Laser Guide Star(Forwarded)

W.M. Keck Observatory
Kamuela, Hawaii

Media Contact:
Laura K. Kraft, (808) 885-7887

January 10, 2006

Scientists See Better, Fainter with New Keck Laser Guide Star

WASHINGTON, D. C. -- A new sodium laser is giving 50 times more sky
coverage to the atmospheric-correcting technology known as adaptive optics
on the Keck II telescope at Mauna Kea, Hawaii. The laser lets scientists
explore most of the sky with adaptive optics and gives them the capability
to study objects that were previously too faint to be seen with the
system. Since 1999, Keck Adaptive Optics has provided 10 times more
resolving power than what could otherwise be achieved from the ground. The
results are producing infrared images from the ground comparable -- and
often better -- than those taken from space.

"This has been the most exciting technological and scientific breakthrough
for the Observatory in the last decade. It may forever change the way we
do astronomy from the ground," said W. M. Keck Observatory Director Fred
Chaffee. "We are entering a new, extraordinary era of discovery."

After just one year of regular scientific use, the Keck Laser Guide Star
Adaptive Optics system is producing spectacular results and advancing
research in several fields of astronomical study. Findings include the
discovery of new asteroids, moons and planetoids in our solar system, the
detection of new brown dwarf binary systems -- including a strange new
kind of binary, observations of physical processes taking place near a
supermassive black hole, and new findings about extremely distant
supernovae and young galaxies.

The technique of adaptive optics uses visible light from a bright star to
measure and correct for atmospheric distortions at infrared wavelengths.
But only about two percent of the sky has stars bright enough to use with
adaptive optics. The Keck Laser Guide Star system overcomes this
limitation by creating an artificial star anywhere in the sky. The W. M.
Keck Observatory is the only 8-10 meter class facility in the world
currently providing this capability to observers.

"The wish list for astronomers is pretty simple," said Dr. David Le
Mignant, adaptive optics scientist at the W. M. Keck Observatory. "First,
they want the highest-quality images that can possibly be obtained.
Second, they want to look anywhere they want to in the sky. The laser
guide star makes both these wishes come true."

Operating at nearly 1,000 times a second, the Keck adaptive optics system
minimizes the blurring effects of Earth's atmosphere to provide infrared
images 10 times better than what can be achieved from the ground. Without
any correcting technology, the best telescopes on Earth are limited to an
average "seeing" ability, or resolving power, of about 0.5 arcseconds, the
equivalent of being able to distinguish an object the size of a blueberry
from 2.5 miles (4 km) away. But with adaptive optics, atmospheric blurring
is removed, producing a resolving power of about 50 milliarcseconds or
better. This improvement is like looking at a penny from 2.5 miles away
and being able to read the words, "ONE CENT" and "Liberty" stamped on the
coin.

"We are shattering a limitation for ground-based observations --
astronomers can now uncover and study fine structures in extremely faint
objects anywhere, within and beyond our galaxy, " said Dr. Le Mignant.
"This new data will particularly complement present deep sky surveys which
study the formation of galaxies in the universe."

More than 21 scientific results made possible with the Keck Laser Guide
Star system are presented today at the 207th meeting of the AAS in
Washington D.C. Among the many new significant findings discussed at
Special Session 98, "Seeing the Universe in a New (Sodium) Light":

* In the distant regions of our solar system, scientists at Caltech have
used the Keck Laser Guide Star to discover three new satellites orbiting
some of the largest objects in the Kuiper belt. The surprising properties
of these moons suggest that they are formed very differently from the tiny
moons known to orbit smaller Kuiper Belt Objects. (A. Bouchez, Caltech)

* At the center of our own Milky Way galaxy, the hostile environment
around the supermassive black hole should make it difficult for stars to
form, but a group of massive young stars has been detected and their
origins are puzzling scientists. The problem has been dubbed "the paradox
of youth." Now, UCLA scientists are able to measure how these young stars
move across the sky with an unparalleled precision of only two kilometers
per second, and determine, for the first time, the orbit of each of the
young stars located more than a few light months from the black hole.
Scientists are using the stars' orbits, which retain an imprint of their
origin, to understand how and where these young stars may have formed. (J.
Lu, UCLA)

* Also in the Milky Way, scientists at the University of Hawaii are
discovering new ultracool brown dwarf binary systems, including a strange
new kind of binary never seen before. (M. Liu, UH-IfA)

* Scientists at UCSC and the Supernova Cosmology Project observed a
supernova in a galaxy as it appeared when the universe was only 40 percent
its current age (z=1.3). The Keck Laser Guide Star system allowed the team
to study the faint system and resolve the supernovae from the galaxy core,
separated by only 0.4 arcseconds. The discovery was made as part of a
major, long-term project called "Center for Adaptive Optics Treasury
Survey" or CATS, a project that is looking at deep Hubble galaxy fields
with the Keck Laser Guide Star System. (J. Melbourne, Lick/UCSC)

"Major advances in astronomy are often the driven by having new
technologies to explore the heavens," said Michael Liu of the Institute
for Astronomy at the University of Hawaii. "Through years of effort and
dedication of many people, the Keck system is allowing us to see the whole
of the universe in a new (sodium) light."

More than 20 percent of all available observing nights through July 2006
on the Keck II telescope will use the sodium laser. Laser guide star
systems do not outperform natural guide stars, but rather take over in the
faint skies where sufficiently bright stars do not exist. With bright
objects of magnitude 10 or greater, natural guide star systems still
provide slightly better images, and will be used for about 30 percent of
the adaptive optics research at W. M. Keck Observatory.

The Future

Regularly using sodium lasers with adaptive optics is in its early stages,
but laser guide stars are being developed for most major observatories,
most notably the European Southern Observatory's Very Large Telescope, the
Gemini North and Gemini South telescopes and the National Astronomical
Observatory of Japan's Subaru Telescope. Plans are also underway to
install a new laser guide star system on the Keck I telescope within the
next three years, and also to improve the efficiency and reliability of
the existing laser system on Keck II.

Acknowledgements

The W. M. Keck Foundation provided major funding for the construction of
the twin 10-meter Keck telescopes and for the adaptive optics and laser
guide star systems. Additional funding for the Laser Guide Star Adaptive
Optics system was provided by NASA, Lawrence Livermore National Laboratory
(LLNL) and the Center for Adaptive Optics. The Laser Guide Star Adaptive
Optics system was implemented by a team at W. M. Keck Observatory. The
sodium laser was developed at LLNL. The W. M. Keck Observatory is managed
by the California Association for Research in Astronomy, a non-profit 501
(c) (3) corporation whose board of directors includes representatives from
Caltech, the University of California and NASA.

IMAGE CAPTIONS:

[Image 1:
http://keckobservatory.org/news/scie...egg_nebula.jpg (173KB)]
Egg Nebula as seen with the Keck II Laser Guide Star Adaptive Optics
system

This protoplanetary nebula is reflected light from a dying star that is
shedding its outer layers in the final stages of its life. As more and
more material is lost from the star¹s surface, the surface temperature
will become hotter, allowing ultraviolet light to ionize the emitted
gasses. This process typically results in a planetary nebula in a few
thousand years.

Composite image of near-infrared wavelengths (1.65, 2.12 and 2.29 microns)
obtained in July, 2004. FOV = 15.8"x23.7"

Image credit: LGS-AO Engineering Team/Keck

[Image 2:
http://keckobservatory.org/news/scie..._lgs/19292.jpg (226KB)]
Protoplanetary nebulae IRAS 19292+1806. Composite near-infrared (1.25,
1.65, 2.2, 3.45 microns) obtained in July, 2005. FOV = 2"x2"

Image credit: LGS-AO Engineering Team/Keck

[Image 3:
http://keckobservatory.org/news/scie..._lgs/17347.jpg (68KB)]
Protoplanetary nbulae IRAS 17347-3139. Composite near infrared image (
2.2, 3.45, 4.7 microns) obtained in July, 2005. FOV = 3"x3"

Image credit: LGS-AO Engineering Team/Keck

[Image 4:
http://keckobservatory.org/news/scie..._lgs/19255.jpg (150KB)]
Protoplanetary nebulae IRAS 19255+2123. Composite near-infrared (1.65,
2.2, 3.45, 4.7microns) obtained July 2005. FOV = 4"x4"

Image credit: LGS-AO Engineering Team/Keck