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The McGregor Observatory
- and -
The 13" f/10 Schupmann Telescope

In the late 1980's and the first half of the 1990's, the Springfield Telescope Makers undertook a huge project - the construction of a new roll-off-roof observatory and a 13" Schupmann telescope. This 8-year project really taxed the club and required a huge effort. However, the results are outstanding: The 13" Schupmann is truly a world-class telescope and the observatory is a rugged, functional building that houses not only the telescope, but provides space for a browsing library, the annual mirror class and many activities during convention. These pages document the construction, dedication and early use of this facility.

McGregor Observtory
The McGregor Observatory
The McGregor Observatory in 2006 open for solar observing
The McGregor Observatory in 2006
open for solar observing

The McGregor Observatory

McGregor Observatory
Construction Photo Gallery

Built by the Springfield Telescope Makers on top of a south facing hill on the recently acquired Stellafane East, with "more concrete in it than the Hoover Dam", the McGregor Observatory is the large white building you see when entering the site. Led by John Martin, the construction effort took over 5 years in often difficult weather conditions.

The observatory has three major rooms: The telescope room under the roll-off roof; the first floor warming room under the fixed roof, and the control room on the second floor under the fixed roof. This set of photos documents that monumental effort.

McGregor Observatory Precise Location

In August 2022, member George Springston used rectified aerial orthophotography to determine the location of the telescope pier to sub-meter accuracy. It is at 43.27687326° north latitude and 72.51380296° west longitude, NAD83 datum.

Schupmann Telescope / McGregor Observatory Dedication

By Maryann Arrien, August, 1996

McGregor Artwork
The McGregor Observatory
McGregor Observatory Painting by Russ Chmela
McGregor Painting by Russ Chmela

On Saturday, July 15 1995, the town of Springfield Vermont became home to another unique astronomical observatory.

The McGregor Observatory, as it is called, was dedicated by the Springfield Telescope Makers to the memory of their member Douglas McGregor. It houses a telescope which at this moment is the largest operating one of its kind in the world. It is a 13-inch f/10 diffraction limited Schupmann design, which combines refractive and reflective optical elements to create an unobstructed, coma and color free image. This makes it especially suited for observations of the planets. The optics, as well as the observatory itself, were fashioned 'from scratch' by club members in their spare time over an eight year period.

McGregor/Schupmann from the Air
The McGregor Observatory
The McGregor Observatory, roof open, red Schupmann Telescope visible.
The McGregor Observatory, roof open,
red Schupmann Telescope visible.

McGregor, of St. Johnsbury, Vermont, was an avid amateur astronomer and telescope maker who was best known as Master of Ceremonies of the Stellafane Convention up to the time of his passing in 1988. The close knit club reacted to the sudden loss of McGregor by undertaking this ambitious observatory project in his name. The McGregor Observatory was designed and largely built by his close friend John Martin V of Chester, VT. He, Charles Thayer and other members of the telescope making club set about building the observatory structure atop a granite rise. Meanwhile, optical designer Scott Milligan and master optician Philip Rounseville spent countless hours of labor on the telescope. It is a tribute not only to their Yankee ingenuity and amateur zeal that this unique observatory was created, but largely to the inspiration of their comrade, Doug McGregor, who loved stars and telescopes as much as anyone ever did.

Stellafane Browsing Library

The first floor warming room in the McGregor Observatory is home to the Stellafane Browsing Library. This article is about the dedication of the library in 1998 to Jeanne C. Krzywicki.

The 13" f/10 Schupmann Telescope

The Springfield telescope Makers have built the world's largest "Super-Schupmann" medial telescope. The "Super-Schupmann" is an all spherical design that is essentially color-free, and the scope may be user adjusted in the field to tune out any residual color due to thermal expansion or atmospheric refraction (especially noticeable near the horizon where the atmosphere is thickest to view through). The following articles provide information on the creation of this outstanding telescope.

The 13" f/10 Schupamnn Telescope
The 13-inch f/10 Schupmann Telescope
Stellafane's 13" f/10 Schupmann in the McGregor Observatory (Photo by Maryann Arien)
Stellafane's 13" f/10 Schupmann
in the McGregor Observatory

Ludwig Schupmann &
Some Early Medial Telescopes

Jim Daley, club member and Schupmann expert, provides details about Ludwig Schupmann (1851-1920) and some of his early instruments.

If you are interested in the Schupmann telescope design, you might want to read Jim Daley's recent book1 about the Schupmann Telescope.

Building the World's Largest Schupmann

Scott Milligan chronicles the 10-year odyssey that he and Phil Rounseville had in fabricating the optics for the Stellafane 13-inch f/10 super-Schupmann. This 7-page article is great reading if you want learn the problems and unique solutions this pair came up with to create the superb instrument that now graces the McGregor observatory.

Some folks have questioned our claim that this is the world's largest Schupmann. As far as we know, at the time of it's construction, it was is the world's largest super-Schupmann, which is an all-spherical design with perfect color correction. There were clearly Schupmanns with larger objectives out there, but they are of the older designs with good, but not perfect color correction. Since the writing of this paper, Jim Daley has been working on a 14.1-inch super-Schupmann, and by the time you read this it well may be completed, and he can claim the title of building the world's largest super-Schupmann.

Optical Schematic
The 13-inch f/10 Schupmann Telescope
Optical Schematic of Stellafane's 13-inch f/10 Schupmann by Russ Chmela
Optical Schematic by Russ Chmela

Press Release from Dedication

This is fairly technical press release issued at the dedication of the Stellafane 13-inch f/10 Schupmann Medial Telescope, and summarizes all the key points in the all-spherical "super-Schupmann" design.

Observing with Stellafane's Schupmann Refractor

Carl Breuning's recounts his first observations using our Schupmann Medial Refractor.

A Tale of a Counterweight

John Martin recounts the thinking and process that went into creation of the 7-inch binoculars used for a counter weight on the Schupmann mount.

CCD Images

Early CCD images taken by John Martin with the Stellafane Schupmann Refractor. John has done some work with video cameras on the Schupmann also; see his Astrophotography Page for more images.

Photo of Mars by John Martin
The 13-inch f/10 Schupmann Telescope
Photo of Mars through the Stellafane Schupmann by John Martin
Mars
Photo of Saturn by John Martin
The 13-inch f/10 Schupmann Telescope
Photo of Saturn through the Stellafane Schupmann by John Martin
Saturn
Photo of Jupiter by John Martin
The 13-inch f/10 Schupmann Telescope
Photo of Jupiter through the Stellafane Schupmann by John Martin
Jupiter

1The Schupmann Telescope: The Story, Design, Construction and Use of a Neglected Telescope Type
by James Daley, 200 Pages Hardbound, Willmann-Bell, Richmond, VA, 2007 ISBN-13: 978-0-943396-59-0.

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