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Terry Wood

Jupiter (clearer) Nov 5th 2023 w/Mewlon 180c

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11.2-inch f/6.75 *Zerodur* Pegasus Mirror – Ready to Use!

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John Hall of Pegasus made this mirror for me to use in a planetary Dob. Time passed and the scope never got built, so now this fine optic is looking for a new home. The mirror blank is Zerodur, an ultra-low expansion (ULE) ceramic that holds its shape even with wide swings in temperature. It features a super-smooth paraboloid figure and he rated it at ~ 1/50 wave RMS. The focal length is on the long side at 75.6 inches, making for easy collimation, a small secondary, and it can be used with almost any type of eyepiece.

The coating was done by Spectrum in Florida and features their enhanced reflectivity, ion-assisted aluminum and protective overcoat. The mirror has been in sealed storage and today the coating looks perfect in every way.

11.2” (284 mm) diameter

1.32" (34 mm) edge thickness

10.9 pounds (4.95 kg) weight

75.6” (192 cm) focal length, f/6.75

Zerodur ULE blank, ground flat on the back, bevel on front edge

Enhanced aluminum coating

Buyers can pick up the mirror in Tucson, or I will ship at actual cost for carriage and insurance.