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Grasslands Observatory :
Operations |
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Looking North during the day |
At the gate looking South to the Observatory |
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Achernar culminating on the Southern Horizon 4 Nov 2005, 11:20
pm MST; Altitude 1 deg, Azimuth 182 deg; Magnitude 0.54 |
Gacrux (the top star in the Southern Cross)
culminating on the Southern Horizon 18 May 2007 9:40 pm;
Altitude 0.5 deg, Azimuth 184 deg; Magnitude 1.65 |
The Grasslands Observatory 18 May 2007 |
Venus and the Moon 18 May 2007 |
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Night at the Grasslands Observatory. |
The Director of the Observatory is James McGaha who is a retired
Air Force Major and a former C-130 pilot. He has a Master's
degree in astronomy as well as an MBA degree. James directs the
scientific program at the Observatory, which consists of
asteroid astrometry, asteroid recovery, and asteroid discovery,
as well as supernova photometry, and
Tri-Color CCD Imaging.
Since 1995, the telescope and its associated instruments have
been operated from the Control Room. This building is a small,
one-room, well insulated house with lights, heat!!, a
refrigerator, microwave, futon, chairs, and a Control Console
for operating the telescope. The Control Console is connected by
cables running through a metal conduit to the main Observatory
Building. The Control Room Computer is networked to three
computers in the Observatory Building, the Telescope Computer,
the ACE Computer,
and the Guider Computer.
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The Control Room |
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Control Room from Left |
to |
Right |
Control Console |
The 24-inch f/5 telescope is fully computerized. It formerly had
to be manually moved from position to position. Now, it is
completely operated from the Control Room by a sophisticated
control system installed by
Astronomical Consultants & Equipment, Inc. (A.C.E.) of Tucson,
Arizona. This system allows for accurate all sky pointing of the
telescope, and it has a built in periodic worm correction
encoder. It works in conjunction with an SBIG ST-402 ME CCD camera
for long exposure guiding. In addition, a new mirror cell with
built in tube fans was constructed for the telescope by A.C.E., and Losmondy mounting plates were installed on the telescope to
carry a variety of instruments.
Ancillary equipment includes an 8-inch f/4 Meade LXD55
Schmidt-Newtonian telescope which has been mounted onto the side
of the 24-inch telescope. Imaging through the 8-inch telescope
is done with a Canon 20da digital camera back.
In addition, a
Takahashi Epsilon 180 Astrograph is available for mounting on
the 24-inch telescope. Moreover, in early January 2007 a
Celestron C-14 with exquisite optics was permanently
mounted inside of the Grasslands Observatory building.
This telescope is used for visual observing and web cam imaging
of the Moon and Planets.
An Apogee AP7
CCD camera was used for imaging until September 2000. Among its
accomplishments was the imaging of all 338
Arp Galaxies and
tri-color imaging of all the
Messier
Objects. In September 2000, the AP7 camera was transferred
to the 3towers Observatory
in Tucson. It has been replaced by a
Fingers Lake
Instrumentation Dream Machine CCD. Prior to the AP7, an
HPC-1 camera had been used, and some of its images are still
posted on this web site. The HPC-1 was a very fine camera with 12
micron pixels and a 1024 x 1024 pixel array. Its quantum
efficiency was good in the red and green portions of the
spectrum, but it had a relatively low quantum efficiency in the
blue portion of the spectrum. The Apogee AP7 camera has a very
sensitive SITe 512 x 512 chip with 24 micron pixels. It was
attached to an
ISIS
FW1 filter wheel containing an open slot, a clear filter,
and standard R, V, B, and I (near-infrared) Photometric filters.
Now, the
Fingers Lake Instrumentation Dream Machine CCD camera is
combined with a Finger Lakes CFW-1 Color Filter Wheel using
Photometric R, V, and B filters. The AP7 gave a field of view of
14 minutes. The Dream Machine has a chip with a similar
quantum efficiency as the AP7, but the chip is twice as large
(1024 x 1024) and gives a nearly 28 minute field of view.
Focusing is performed with an
Optec TCF
(Temperature Compensating) digital electric focuser. At the
Control Console, a Pentium 4 2.6 GHz Control Room Computer
running under Windows XP is networked to the three computers in
the Observatory Building, the Telescope Computer The
ACE Computer, and the Guider
Computer. The Observatory Building computers operate the
telescope, the CCD camera, the filter wheel, the focuser, and
other ancillary equipment. The Telescope Computer in the
observatory consists of a Pentium 4 2.4 GHz system running under
Windows XP. It operates the Dream Machine CCD camera and the
filter wheel. The ACE Computer is a Pentium (R) D CPU 3.20
GHz system that controls the telescope pointing and drive system
using the sophisticated A.C.E. control system. The Dream Machine CCD camera
is controlled with
MaxIm DL/CCD.
The CCD is oriented on the telescope such that all images
are displayed on the computer screen with the North to the top
and East to the left.
A Pentium 4 2.4 GHz Guider Computer is also networked to the
Control Room Computer, the ACE Computer, and the
Telescope Computer. It runs the
software and hardware for an
SBIG
ST 402 ME CCD camera mounted on a Celestron 8-inch f/10 telescope.
The C-8 is attached to the 24-inch telescope, and the ST 402 ME
guider is used for long exposures to correct periodic error
drift and other drive errors. The Dream Machine CCD camera
creates images that are over two megabytes in size. These are
read from the CCD camera over the network directly to the
Control Room Computer. In order to take the raw data home for
processing, a CD disk writer on the Control Room Computer is
used to make data disks for long term archival storage and for
taking data home.
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| Telescope at night |
Dream Machine CCD Camera |
Telescope with CCD Camera |
tbh, Saturday 28 April 2007
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Take Time to Smell the Flowers:
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This wild flower was photographed at 1:20am on 14 April 2001 by
James McGaha with his new digital camera. We noticed the wild
flower as we were returning from a night's observing run. The
flower grew alongside the dirt road going back to the
observatory building. It was visible in our car headlights. The
entire 20 acres of property at the Grasslands Observatory was
covered by these flowers. Mike Newberry
of
Mirametrics, Inc.
(Mira)
writes: "The flower James photographed is Oenothera caespitosa,
or "evening primrose". "Caespitose" means growing in clumps or
tufts. The flower opens in evening twilight and withers in
morning twilight, lasting only 1 night. Other flowers or flowers
on other plants will open the next night. It grows at 3000 to
7500' elevation in gravelly places. About 20 species of
Oenothera are in Arizona." |
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