The History of the KPNO 0.9m Telescope:
Opened in March 1960, the National Science Foundation's 0.9-meter telescope
was the first major telescope at Kitt Peak National Observatory.
After 41 years of service to NOAO, operations of the 0.9m
were transfered to the WIYN consortium in February 2001. Despite its relatively small aperture,
the 0.9m is a
popular instrument because of its large field of view.
This website recalls the history of the 0.9m,
with a virtual tour, a pictoral description of a
typical night at the telescope,
a gallery of images taken with the 0.9m,
and anecdotes from some of the many astronomers who have
observed with this remarkable instrument. You may click on any image to see an enlarged version.
A Virtual Tour:
When most people imagine astronomers at work, they envision someone sitting in
a dome looking through an eyepiece on a telescope. The reality for astronomers is very different.
Rather than look through an eyepiece, we use sensitive electronic cameras.
And instead of sitting beneath the telescope in a freezing cold dome, we
reside in a warm control room in front of a computer which controls the telescope and camera.
This virtual tour shows the different
parts of the 0.9m, a typical research-class telescope.
The summit of Kitt Peak as seen from the Mayall 4-meter telescope.
Kitt Peak National Observatory:
Fifty six miles
west of Tucson, Arizona lies
Kitt Peak on the
Tohono O'odham reservation.
The national observatory resides at the summit of Kitt Peak at 6750 feet. The 0.9m telescope is
just below and to the right of
distinctive peak at the center of the image.
The WIYN 3.5m and KPNO 0.9m telescopes.
In 1966 a second 0.9m telescope was opened on Kitt Peak, just east of the original.
Both operated until 1990, when the
original 0.9m site
was cleared for use by
the WIYN 3.5m telescope (on the left). The first
0.9m telescope was then moved into the No. 2 dome (right). The second
0.9m was moved to a northern location on Kitt Peak, and operations
were assumed by the
The dome of the 0.9m telescope on Kitt Peak.
Outside the No. 2 Dome:
The telescope resides on the second floor of the building.
It is enclosed in a dome to protect it from wind, rain and
Eleven dome vents were installed in August 1994 to increase airflow through
the dome, which has significantly improved the image quality. The dome makes an
awful noise each time it moves.
Listen to the dome as it moves.
The control room for the 0.9m telescope.
Operating the Telescope:
On the ground floor is the control room. Astronomers operate the telescope
from here, allowing them to stay out of the cold. The computer on the far right is used
to control the electronic camera and the computer in the center is used to move the telescope,
as well as
process the data. The console on the left is also used to move the telescope manually.
The work area in the back of the control room.
The Modern Amenities of Life:
Weather permitting, astronomers use every moment of darkness, observing from dusk
until dawn. In the winter, nights can be as long as 14 hours, making for hard work.
The back of the control room has a
microwave oven, refridgerator and coffee maker to help the night pass more easily.
In 1998 the darkroom was removed to create this space.
The telescope control system in the computer room.
The Computer Room:
The computers which operate the telescope and instrument are kept in a climate-controlled
room on the ground floor. The wooden crate to the lower right carries the workstation
which controls the electronic camera. Amazingly enough, the telescope itself is still controlled by
an old Digitial PDP-11/73 computer (on the left), which was installed in 1970.
The stairs up to the dome are lit at night for safety.
Up to the Telescope:
The telescope itself resides on the second floor of the building, away from the
heat and light pollution from the control room. Astronomers use an intercom in the control room
to hear what's going on in the dome.
The 0.9m telescope. Mosaic is attached to the bottom.
The telescope mount was constructed by Boller & Chivens in 1965. The name of
the telescope reflects the 36" diameter of the primary mirror.
is the electronic camera seen
on the bottom of the telescope. With this camera,
the telescope offers an unprecedented 1 square degree field of view (which is about five times the area of the moon) with subarcsecond
Listen to the telescope as it moves.
Six of the eleven dome vents as seen from inside the dome.
Eleven individually controllable dome vents may be opened to allow air to flow through the dome while observing.
When open, the air within the dome is flushed out several times per minute, eliminating warm air
pockets which can degrade image quality. The vents are closed if gusts of wind cause the telescope
The dome shutter is opened at twilight.
Door to the Heavens:
The telescope views the sky through the dome shutter. The dome shutter is
kept closed to protect the telescope during the day and during bad weather.
To learn more about how the telescope is actually used you may read about a
typical night at the 0.9m.