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July 09, 2008
"A Not-so-Brief History of Time"
[Or..."How the Onan Observatory Came About"]
Telescope as installed in Duluth, ca. 1980. Photo Credit: A.
Ominsky [Click for larger picture]
In 1973, a group of amateur astronomers
originally associated with the 3M Astronomical Society formed the Twin Cities Astronomy Club. As the club grew and its public
outreach activities flourished, its members realized the Twin Cities would
benefit greatly from a public observatory. In preparation for the task of
soliciting the necessary donations, the club sought and obtained 501 (c) 3
nonprofit status in 1976.
Through its involvement with programs at the University of
Minnesota, the club learned that the astronomy program at the Duluth campus wished to
dispose of its primary instrument, a Group 128, 16" Cassegrain
telescope. A Ms. Larson, aunt of a member, loaned the club the bulk of $6,500 needed to purchase the
and in May 1980 a group removed the telescope from its Duluth location and
transported it to the Twin Cities. (In recognition of Ms. Larson's
support, the club officially designated the telescope as the "Larson
Telescope", a name which it bears to this day.) The club disassembled
the 1,000 lb. telescope and moved it to storage sites in Burnsville and Forest Lake Minnesota.
Realizing its unique position of providing an astronomical organization for all
of Minnesota and not just the Twin Cities, the club changed its name
to the Minnesota Astronomical Society in September of 1980.
|In 1987, after a 12 month selection process which considered nine
public and private locations around the Twin Cities, the Society selected Baylor Regional Park,
near Norwood-Young America, as the preferred site for the observatory. During
the following year, the members of the Society's Observatory Committee navigated the long, arduous process
needed to gain approval for construction at Baylor. The first major step was to amend the Baylor Park
Master Plan to include an observatory. This amendment subsequently
required approval by the Carver County Park Commission, the Carver County Board,
the Metropolitan Parks and Open Space Commission and the Metropolitan
Council. Additionally, the park's Conditional Use Permit was amended to
add the observatory as a park use. The Carver County Planning Commission and the Carver County board subsequently
approved this change. Finally, the MAS and the County drafted a 20 year
lease covering the use of Baylor Regional Park as the site for a public
observatory. Representatives of the Society signed the lease on September
21, 1988 and the Carver County Board of Commissioners unanimously approved the
lease on November 8, 1988.
Cover of the 1990 proposal, showing
original design of observatory. [Click for larger picture.]
Letter from Mary Williams, describing her intent for the $20,000 grant.
[Click for larger picture.]
Over the next several years, the Society worked to design the planned
observatory. Finally, in 1990, plans were sufficiently complete to
support the first construction fund-raising effort and in 1990 and 1991 the
Society contacted 175 potential funding organizations. Preliminary
estimates suggested construction costs for the planned observatory would range from
$75,000 to $80,000, with an additional $31,000 required for equipment.
After months of fund-raising only one organization -- the
Onan Family Foundation -- responded favorably, providing the Society with a
$20,000 grant to begin constructing the observatory.
After the relationship with Wilder ended, the Society recommitted to
constructing an observatory at Baylor Regional Park. In 1993, the Society
developed a new, scaled down design for the observatory, thought to be more
achievable given the then-current state of financial affairs. This design
became known as the "shed on a hill" approach, because of its simpler,
almost Spartan approach to housing the telescope.
In 1994, the Society engaged the architectural firm LOOM to review the
proposed design and evaluate it. The review identified a number of flaws
and shortcomings. As an alternative to the "shed on a
hill" observatory, LOOM proposed a unique roll-off roof design which became
known as the "three short-barreled shells" design. Through the remainder of
1994 and into 1995, LOOM refined the design. The membership of the Society and the Carver County Parks
Commission both approved the conceptual design.
Progress on the observatory inched along through 1996 and 1997, as the
Society's attention and energies turned toward sharing with the public the two
great comets of those years -- Hyakutake and Hale-Bopp. In total, well
over 1,500 people joined the MAS at several public viewing events.
Interest in astronomy was high and the Society's membership -- and commitment
to the observatory project -- benefited greatly. Late in 1996, a small
group of Society members formed the "OTC Committee" with the sole purpose of either getting
the observatory constructed, or, pushing the telescope "Over The
Cliff" (hence the committee's acronym).
1997 saw a renewed focus and energy applied to the project. The OTC
Committee solicited and received approval to proceed with the LOOM design from the Executive Board and
membership of the MAS, as well as from the Carver County Parks Commission and
the Carver County Board. The MAS Executive Board
allocated money from the original 1991 Onan Family Foundation funds and construction
of the observatory was finally underway.
Page from the original LOOM pre-design
document showing proposed observatory. [Click image for larger picture]
Forms for the telescope pier and foundation footing, ready for concrete late in 1997 (click image for
The two months of September and October, 1997, saw more real progress toward observatory
construction than any two prior years combined. In this short period of
time, the OTC Committee:
Finalized the design details sufficiently for LOOM to produce
Contracted for soil testing at the proposed site
Solicited bids for masonry materials and dirt work, letting out
contracts for both
Delivered the telescope's optics to a local optical expert willing to
take on the arduous task of correcting the complex optical figures of the
Obtained the volunteer services of a masonry class from Hennepin
Technical College to construct the
telescope pier and the buildings' footings, foundations and walls, and,
Kicked off a capital fund-raising effort with a $10,000 goal.
October and November were no less busy. Dozens of
MAS members showed up weekend after weekend, striving to complete the retaining
wall ringing the observatory's 40' diameter terrace before winter set in.
The instructor and students from Hennepin Technical completed pouring of
the foundation and telescope pier, and began the task of constructing the
concrete block walls of the observatory.
The members of the MAS finished the retaining wall late
in November, just as snow was about to fly. Working under a dome of
plastic sheeting, the Hennepin Technical volunteers worked under quasi-heated
conditions and completed the walls in December. The final major
accomplishment of 1997 was to relocate the +1,000 lb. telescope mount from
storage to the work space where renovation would take place in the months ahead.
The focus of the first few months of 1998 was
fund-raising. MAS members and companies such as 3M and Zeiss IMT combined
to exceed the original $10,000 fund-raising target, by contributing over
Site at the close of the 1997 construction
season. (Click on image for a larger, panoramic view).
A volunteer supporting an assembled roof
section. Photo Credit: D. Olmstead (Click image for larger picture.)
The start of the 1998 construction season presented the
Society with its most formidable physical challenges to date. During
this time 170 cubic yards of clay was moved onto the site and used to backfill
the foundation and surrounding landscape. Construction of the roof
roll-off mechanism followed, requiring fabrication of 14 mounting brackets and
wheels, installed along a 50 foot span in perfect alignment. And then,
attention turned to the construction of the roof itself. Hundreds of
prefabricated pieces, totaling over 2,000 pounds, were assembled by volunteers of
the MAS, with many of the arches requiring assembly at a height of 19 feet above
ground. The final major construction activity for 1998, was the
installation of electrical service to the site.
saw the completion of two major milestones -- the pouring of the
observatory floor and the installation of the large door located in the
end of the movable roof section, enabling the unobstructed motion of the
roof across the observing floor. Inside the building, the concrete
floor was finished and sealed, and the final electrical wiring
installed. Doors were installed throughout the building and the
refurbished mount for the telescope was installed on the pier.
Installation of the moveable roof's door. Photo
Credit: D. Olmstead (Click
image for larger picture.)
Major construction progress
continued in 2000. The temporary enclosures at the ends of the
buildings were replaced with translucent panels, allowing outside light
into the observatory during daylight hours. Installation of
florescent lighting provided nighttime illumination of the building's
In April, the refigured optics and tube assembly of the Larson
Telescope were reassembled and mounted on the observatory's pier.
By the end of the year, the telescope was fully operational, including
the addition of a state-of-the art electrical focuser, a top-of-the-line
finder scope and electronically-driven stepper motors to drive the
telescope. This major milestone marked the end of a 20 year
journey for the telescope that began when it was first moved from the
University of Minnesota, Duluth.
The ongoing struggles with the motion of the roll-off roof were
finally resolved by reengineering supporting brackets, thereby
strengthening them and by replacing the rolling wheels with
non-deforming steel wheels. At the public event of June 24th, the
observatory roof successfully rolled back for the first time since the
Larson Telescope arrived on site.
Financial support for the observatory continued through the
year. In addition to substantial contributions of time and money
by members of the Minnesota Astronomical Society, the Onan Family
Foundation continued their generous support with a grant of $10,000.
|The inaugural season of public programs opened April 28th, 2000 with over
100 visitors in attendance. Public programs and small-group educational
programs continued throughout the summer and fall, serving hundreds of
Twin City's residents. Though much remained to be done, the
Minnesota Astronomical Society's Onan Observatory at Baylor Regional
Park was finally up and running!
Visitor using Larson Telescope Photo
Credit: B. Huset (Click
image for larger picture.)
Custom cabinets featuring pull-out library (click image for
|In the years the followed, many improvements took place
at the observatory.
Custom-fabricated cabinets and a pull-out library unit were added in
2001. The MAS also hosted a star party for members of the
Astronomical Society of the Pacific who were in Minnesota for a
convention and welcomed almost 350 visitors at its Leonid meteor shower
2002 saw the construction and installation of portable benches that
double as additional storage.
Most of 2003 activities at the observatory centered on general
maintenance and repair, and keeping pace with the nearly 2,000 visitors,
a number largely driven by all the 'press' the close opposition of Mars
generated that year.
| In 2004, manual opening and closing of the
observatory roof was eliminated by adding a winch-driven roof mechanism.
Shielded lights we added to several park buildings to eliminate glare at
the observatory. The observatory also received two equipment
donations during the year -- a CCD imaging system, and a Coronado H-Alpha solar
telescope. Giant 15x80 binoculars were also added to the inventory
Roll-ff roof winch mechanism (click image for
As we enter 2005, renovation and improvement of the Larson telescope continued
with improvements to its primary mirror cell and changes to the tube to reduce the amount of light
potentially impinging on the primary mirror and secondary mirror cell
and supports. The observatory also took possession of its latest
donation -- a Takahshi TOA-130 refractor on a Temma 2 NJP mount.
Plans for the year include beginning installation of the long-planned
benchwork around the terrace, and construction of a paved path leading
from a proposed handicap accessible parking space up to the observatory
# # #
(Check out the status
reports for the most recent updates.)
(Do you have additional information regarding the history of the observatory
or an interesting anecdote? Please share them with Mike Kibat at