Milwaukee Astronomical Society


Armfield Observatory - A Dome

Armfield Observatory - Ed Halbach TelescopeThe Armfield Observatory is named for Luverne Armfield, the founder of the Milwaukee Astronomical Society who was involved in the early construction of the observatory and an active observer of variable stars and meteors. In fact, he was one of the earliest variable star observers as his AAVSO observer code was "A".

You can read about Luverne Armfield's many contributions here.

This observatory was built in 1937-38 with a 14 1/2 foot dome and houses the Edward A. Halbach reflector, named for Ed Halbach who was one of the earliest MAS members, served as MAS President, Treasurer, and finally as the observatory director for 35 years. He was an active observer for over 70 years.

The first floor contains our restrooms, storage, hallway to our lecture hall, and stairway to the observatory floor.

The scope is a 12.5 inch, f/8.8, Newtonian reflector.  It is usually referred to as the "A" Scope. It sits on a massive German equatorial mount with a clock drive. RA and DEC are positioned using very large vernier setting circles. A limited fine slew capability (paddle controller) is provided for both axes. A 50mm finder is mounted piggy back.

At the MAS we often refer to this scope as the "Planet Killer" as it's been optimized for lunar and planetary observation. Besides its large aperture (12.5 inches), long focal length (f/8.86), and excellent mirror, the secondary mirror was reduced to increase contrast in planetary details, an Olshenko focusing mask and motorized focuser were added for precise focusing as well as an Atmospheric Dispersion Corrector (ADC) to correct for the prismatic effect of the atmosphere.

You can read all about the history of this instrument in our history section here.

A-Scope Image Gallery

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