University
of Wyoming 2.3-meter Telescope (WIRO)
The University
of Wyomings 2.3-meter telescope is located at the Wyoming Infrared
Observatory (WIRO) about 25 miles southwest of Laramie, WY on the
summit of Jelm Mt. and at an altitude of 9656 ft. (2943m). This site
was chosen because: (1) the dryness of the air, an important
consideration for infrared astronomy since moisture strongly absorbs
infrared radiation, (2) comparatively low turbulence in the air above
the mountain, (3) a dark night sky, (4) close proximity to the
University of Wyoming, and (5) pre-existing road, electricity and
phone lines since Jelm was formerly used by the US Forest Service and
BLM as a fire lookout station. The planning for WIRO began in the
early 1970s. Funding for the facility was obtained in 1975 from the
Wyoming State Legislature (contributing 60%) and from the National
Science Foundation (40%). The total construction costs were nearly
two million dollars. WIRO became operational in September of 1977 and
it still ranks as one of the premier infrared observatories in the
world. The weather on Jelm can be extreme Winter temperatures can
drop below -40 F and wind speeds can occasionally exceed 100 mph.
Snow covers the road from October until May and can limit travel on
the mountain to Sno-Cats and ATVs. In the spring and summer,
lightning is a serious threat to the sensitive electronics at the
observatory requiring extensive efforts to isolate and protect this
equipment.
Optical
Design
The design of the WIRO 2.3 meter telescope is a
classical Cassegrain.
This includes a large, concave primary
mirror with a parabolic surface and a
smaller convex secondary
mirror with a hyperbolic shape. This
allows for two optical configurations. At the prime focus the light
from a distant object is brought to a focus about 5 meters above the
primary mirror's surface. This is the location for the main imaging
cameras for WIRO as it provides the largest field of view. In the
Cassegrain configuration an 8" diameter convex secondary mirror
is placed in the converging beam to intercept the light before it
reaches the prime focus and send it back down the length of the
telescope and through a hole in the primary mirror to form a
secondary image about 1 meter behind the primary mirror. This
configuration provides a smaller field of view but a better imaging
scale for smaller astronomical objects. In addition, the location of
this secondary image allows for much larger instruments to be placed
behind the primary mirror on the rear surface of the telescope
structure. The secondary mirror can be "chopped" or wobbled
under computer control to allow for rapid, alternating sampling of an
astronomical object and the nearby, blank sky. This enables the most
accurate measurements at mid-infrared wavelengths since at this
wavelength the "dark" night sky is actually quite bright
and variable.
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Telescope
Structure and Dome Enclosure
The telescope needs to be
precisely pointed and must track across the sky to follow the
apparent motion of an object from East to West as the Earth rotates.
The telescope mount was manufactured by L&F Industries of
Huntington Park, CA at an original cost of nearly $700,000. The
combined weight of the telescope and its mount is about 110,000 lbs.
Of this, 60,000 lbs moves when the telescope is operated. However,
the precise balancing of the telescope means that the 30 tons of
moving mass can be moved with a 1/10 horsepower electric motor. The
drive gears are machined to very close tolerances and are capable of
positioning the telescope with an accuracy of 1/10 arcsecond
(1/36,000 of a degree). The telescope is operated under computer
control in order to model and correct for the flexure of the
telescope structure as it is pointed toward different positions on
the sky. The hemispherical dome, which shelters the telescope and its
instrumentation, is 45 feet in diameter. The dome was designed and
constructed by Observa-Dome Laboratories of Jackson, Mississippi. It
features a 10-foot wide "slit" which can be opened for
observations and rests on 18 rollers such that it can be driven by
three 1 horsepower motors to follow the telescope as it points to
various objects and tracks them across the sky. The telescope and
instrument control room is located in an adjacent building to the
telescope dome. This building also contains a small laboratory for
instrument preparation and repair. The lab features a selection of
tools and a turbofan vacuum pump for dewar and instrument
maintenance. A small machine shop is also available for more serious
repairs!
Living
Facilities
Observers at the 2.3-meter telescope usually
stay at WIRO while observing. The living facilities includes three
dorm rooms(red,
blue, yellow),
a full-function kitchen,
a bathroom, and a living
room. The living room includes comfy chairs a fold-out sofa, and
an entertainment center with a broad collection of VHS tapes. No
satellite dish (yet?) however, a DVD player is available though lacks
of a DVD collection.
Observing
at WIRO
Observing time is allocated on a quarterly
basis to the faculty and students of the Department of Physics and
Astronomy. Interested visitors from outside the department are
encouraged to apply for time on the WIRO 2.3 meter. Scientists
interested in obtaining observing time in the next quarter should
submit a one-page proposal to the the WIRO
director using the one-line request form by the appropriate deadline.
The schedules and proposal deadlines are below. Please read about
WIRO
observing policies before observing.
Deadline Period/Schedule
December 1 January-March
March 1 April-June
June 1 July-September
September 1 October-December
Transportation
to WIRO
Observers going to WIRO generally start from
Laramie and leave town West on 230 toward the town of Woods Landing
and then take 10 South towards the Colorado border. Located on the
left after about five miles on 10 is the WIRO Cathouse and a 5.5 mile
gravel road leading up the mountain. The road up the mountain is
graded occasionally during the summer and is blocked by snow
typically October-May. A Chevy Tahoe
and Avalanche are generally available
to transport personnel and equipment to WIRO. Other maintenance
vehicles are available to replenish the water supply, grade
the road and transport
heavy supplies to WIRO. During the snowy months sno-cats
are available for transportation. A
more recent addition that will hopefully replace the cumbersome
sno-cats are the Mat-tracks that attach to the Avalanche.
The Mat-tracks allow the Avalanche to maintain the road throughout
the winter and allow for a much more comfortable and quicker ride to
the summit.
Current
Instruments
The following Instruments are
available and ready for use at WIRO:
•WIRO-Prime:
a prime-focus imaging camera for the
WIRO 2.3 meter telescope.
•WIRO-Spec:
an integral-field, holographic phase
spectrograph for the WIRO 2.3 meter telescope.
•WIRO-Long
Slit: a long
slit spectrograph for the WIRO 2.3 meter telescope.
Observing
Proposals
A latex form and style file are
available for observing proposals:
•WIRO
Proposal Form (Latex)
•WIRO
Proposal Style File (Latex)
•WIRO
Proposal Form (postscript)
Telescope
and Instrument Manuals
As they become available,
telescope and instrument manuals will be made accessible. Manuals
will soon be available for:
•WIRO
Users Manual (pdf), (web)
•New
Telescope Control System (pdf), (web)
•WIRO-Prime:
2048x2048 Optical CCD camera (pdf), (web)
•WIRO-Spec:
Integral Field Volume-Phase Holographic Spectrograph (pdf),
(web)
•WIRO-Long
Slit: Long Slit low resolution Spectrograph (pdf), (web)
•GAM
(pdf), (web)
•Voodoo CCD
software (pdf), (web)
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Last
updated: 05/04/06
Michael
Pierce (mpierce@uwyo.edu), Andy Monson (amonson@uwyo.edu)
