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| Image: Supermassive
black holes, like the one hidden by a girdle of dust
in this artist's impression, have the mass of up to
a billion suns. They may lie at the center of most,
if not all, large galaxies. Image and caption courtesy
of Monster
of the Milky Way. |
A black hole forms when gravity overcomes all other known forces.
It then collapses to an infinitesimally small size. Although
there is some physical size associated with a black hole, it
is difficult to say what that size actually is. So, formally,
a black hole has no size.
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| Animation: Images taken
from the years 1995 through 2006 are used to track
specific stars orbiting the proposed black hole at
the center of the Galaxy. These orbits, and a simple
application of Kepler's Laws, provide the best evidence
yet for a supermassive black hole, which has a mass
of 4 million times the mass of the Sun. Animation created
by Dr. Andrea Ghez and her research team at UCLA from
data sets obtained with the W. M. Keck Telescopes. |
In fact, a black hole has only three physical principles: mass,
spin, and electric charge. Only one of these, mass, can be
measured confidently. The orbit of a star can be used to determine
how much mass is inside its orbit. Scientists prove the existence
of a black hole by showing that there is a lot of mass inside
a small volume, as determined by the radii of the orbits of
neighboring stars.
To measure the mass of the black hole at the center of the
Milky Way Galaxy, scientists needed to be able to
see the stars as close as possible to the center of the Galaxy.
By tracking specific stars orbiting the proposed black hole
from 1995 through 2006, Dr. Andrea Ghez provided evidence which
established the existence of Sgr A*, a supermassive black hole
at the Galactic Center. Dr. Ghez and her team have now established
that Sgr A* has a mass 4 million times the mass of the Sun.
Listen as
Dr. Andrea Ghez describes the challenge of studying black holes,
which are among the strangest entities in the universe. Learn
more about black holes from Dr. Ghez. 
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Images: (Left) The
Galactic Center without adaptive optics. Image courtesy
of Keck Observatory. (Right) The Galactic Center and
central black hole (labeled Sgr A*) with adaptive optics.
Image courtesy of Keck Observatory and the UCLA Galactic
Center Group.
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“Earth’s atmosphere has air currents similar to those that
you see rising from a boiling pot of water or as steam rising
from hot pavement at midday. These air currents are constantly
rolling, disturbing the incoming light from stars. Keck Observatory
has perfected a system for compensating for atmospheric turbulence,
by measuring incoming starlight thousands of times per second
to correct for distortions. I have watched as the Adaptive
Optics system at Keck Observatory has evolved over the past
10 years, and it is truly a miracle how well this system works.” – Dr.
Mike Liu, Chair of the Keck Observatory Adaptive Optics (AO)
Working Group and Professor of Astronomy at the University
of Hawai`i
With its Laser Guide Star Adaptive Optics (LGSAO) system, Keck
Observatory has firmly positioned itself as the world leader
in adaptive optics astronomy. The Observatory leadership is
committed to an ambitious new technology program designed to
maintain Keck’s leadership role in adaptive optics for years
to come. The Observatory will install a robust new laser on
the Keck I Telescope before the end of 2008, and plans for
a revolutionary Next Generation Adaptive Optics system, consisting
of multiple laser beams, are in the design phase.
“Having Laser Guide Star Adaptive Optics on both telescopes
strongly enhances the discovery potential of our observatory,” says
Keck Observatory Director Taft Armandroff. “Not only does the
new laser provide an additional resource on the Keck I Telescope,
but it also allows for significant improvements in performance
and technological innovation,” explains Armandroff.
The Keck I laser was funded in part by a grant from the National
Science Foundation, and it will provide a low-power pinpoint
of light that can be projected 90 kilometers up into the Earth’s
atmosphere to create an artificial bright star, called a laser
guide star. Keck astronomers use this laser guide star to take
measurements high enough up in the atmosphere to compensate
for distortions, and these measurements provide the basis for
their adaptive optics corrections. The Keck I laser will improve
upon the existing Keck II laser, which has been in operation
since 1999, in several ways. Among its advantages, the new
laser will be:
- brighter;
- more energy efficient;
- mounted on the center of the telescope as opposed to
the side, which means that the laser spot (or artificial
star) will be less elongated and smaller, which will improve
the performance of the AO system;
- easier to maintain; and
- more reliable.
The Keck I laser will double the existing LGSAO capacity of
the Observatory – making this highly sought after technology
more available. Additional funding is being sought from private
philanthropy to pay for the installation and commissioning
of the new Keck I LGSAO facility. Learn
more about this major technical innovation in ground-based
astronomy.
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| Photo: Evening falls over the twin Keck
Telescopes. Photo by Rick Peterson. |
What is the value of a night observing on the Keck Telescopes?
Dr. Paul Butler, an astronomer at the Carnegie Institution
of Washington in Washington, D.C, admits that he recently turned
down an invitation to the White House in order to spend the
night observing at Keck Observatory. Time on the Keck Telescopes
is highly prized, and the process to earn half a night, a full
night, or a few nights of Keck Telescope time is extremely
competitive.
The University of California and the California Institute of
Technology, Keck’s partner institutions, are each allocated
roughly one-third of the available nights. The remaining one-third
of the nights is divided amongst NASA, the University of Hawai`i
(the land manager of the Mauna
Kea Science Reserve), the Observatory Director, internal
engineering and maintenance, and the National Optical Astronomy
Observatory’s (NOAO) Telescope
System Instrumentation Program (TSIP). Through TSIP, NOAO
investments in new instrumentation for Keck Observatory are
traded for a specified number of observing nights. The pool
of potential observers is clearly much larger than the time
available.
The Observatory strives to ensure that the process of allocating
time maximizes the scientific productivity of the world’s largest
telescopes. The telescope schedules are produced twice a year
through a careful series of steps overseen by Keck’s Observing
Support Coordinator, Barbara Schaefer. The telescope schedules
are not computer-generated, but rather finely tweaked by hand,
by Schaefer. It is fair to say that the Observatory’s scheduling
system works, since the scientific output of Keck Observatory
is unparalleled in the world today. Read
more about the process the Observatory uses to allocate
time on the Keck Telescopes, as explained by Keck’s scheduling
guru Barbara Schaefer.
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| Photo: The Keck Telescopes are the most
powerful and productive astronomical instruments on Earth. |
“As long as I can recall I have loved looking at the heavens
and pondering the enormity of the universe.” - Jerry Nelson,
principal designer of the Keck Telescopes and professor of
astronomy at the University of California (UC) at Santa Cruz
As a young man, Jerry Nelson had an affinity for math and science.
Nelson studied physics as an undergraduate at Caltech, where
he dabbled in astronomy. Richard Feynman taught the freshman
and sophomore physics class at Caltech during Nelson’s undergraduate
career. “Feynman’s dynamic style and approach to physics excited
me,” says Nelson. “As a result of his class, I realized that
I could understand physics at a very tangible physical level,
not just in terms of mathematics.” Nelson also worked with
Gerry Neugebauer and Bob Leighton as an undergraduate and was
deeply impressed by the cleverness these mentors employed in
designing and building apparatus, and also by their critical
attention to details. He went on to graduate school in Physics
at UC Berkeley.
After graduating, Nelson worked in astrophysics as a research
fellow at Lawrence Berkeley National Laboratory (LBNL). His
work was heavily oriented towards unusual instrumentation and
electronics. In early 1977 a group of UC astronomers formed
a committee to explore the possibilities for future telescopes
for UC. Because of his instrumentation experience Nelson was
asked to join this group. “This was the opportunity of a lifetime.
Of course, I said yes,” he recalls. The group considered various
possibilities, ranging from a new 3-meter telescope at a darker
site (UC had a 3-meter telescope on Mount Hamilton above San
Jose, but it was suffering from increasing light pollution),
to a larger telescope like others that had recently been built.
After some discussion, Nelson committed to think about the
possibilities of building a larger telescope. Some months later
he suggested that a 10-meter telescope was possible and that
it should be a segmented mirror telescope in order to make
it technically practical. This was the beginning of the story
of the Keck Telescopes. Nelson shares his thoughts on the challenges
of designing the Keck Telescopes in
this short video clip (requires Flash player).
Read more about Jerry Nelson’s pivotal
role in designing the Keck Telescopes.
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“One of the Advancement Office’s
first priorities was to begin building an identity for Keck
that was visually appealing and representative of the uniqueness
of the twin 10-meter telescopes. We retained Creative Communications,
a local design firm in Waikoloa, to design our Keck Observatory
logo in mid-2005. The hexagons represent the number of segments
on the primary mirrors as well as its design.”
– Debbie Goodwin, Director of Advancement, W. M. Keck Observatory
Most non-profits depend on diverse sources of revenue to support
their mission. The Keck Boutique is a way for the Observatory
to bring attention to its prominence in world astronomy - and
simultaneously contribute to the organization’s purpose. The
Boutique offers a distinctive line of gifts and apparel, including
logo-wear caps, beanies, golf gadgets, wine glasses, coffee
mugs, canvas bags, postcards, Frisbee discs, letter openers,
polo shirts, t-shirts, sweatshirts, women's shirts, and youth
t-shirts. Non-logo items include the “What’s
Up in the Universe?” DVD, a Keck
Telescope model kit (be forewarned that this is a very
challenging activity for even the most technical or engineering
minded), and the Keck Star Globe.
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| Photo: A Keck Star Globe, the newest item
in the Keck
Boutique, took close to a year to create and produce.
Inside the water globe is a replica of the Keck Observatory
on top of Mauna Kea. Turn the globe upside down, set
it back on its base, and watch the stars; you can just
imagine the excitement of being an astronomer doing research
using one of the Keck Telescopes! |
“Most everyone who gets an insider’s glimpse of the Observatory
ends up purchasing a KeckWear souvenir,” Goodwin explains. “We
hope our merchandise inspires people to get more involved in
this amazing era of discoveries about our universe,” she says.
Larry Bryan, a regular attendee at Keck Observatory public
lectures, graciously volunteered his time and expertise to
create an online store of Keck merchandise. Preview items in
the virtual store at www.keckobservatory.org/wear/,
or purchase items at www.hawaiishopshere.com/estore/137.
The Headquarters Store is located in the Advancement Office,
and it is open Monday through Friday from 9 am to 4 pm.
KeckWear will be taking its first cosmic journey this March,
when astronauts Rick Linnehan and Japan Aerospace Exploration
Agency's Takao Doi will be wearing KeckWear short sleeve polo
shirts during Space
Shuttle Mission STS-123, scheduled to launch on March 13,
2008. Be on the lookout for photos of KeckWear in space in
an upcoming issue of Cosmic Matters.
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