The Forty Inch Astrometric Reflector

The telescope is an f/13.53 flat-field Baker-Schmidt Cassegrain

effective focal length = 541.4 in = 13751 mm.

focal plane scale = 15.00 arcsec/mm


Corrector: aspheric/plano 1.19 in thick UBK7 glass

Secondary: 19 inch diameter ULE with turned-down edge (2 fringes Hg green line)

Primary: 43 inch diameter ULE, turned-up edge (9 fringes)

Center Hole: 14 inches in diameter


primary-secondary separation: 194.2 inches

primary-corrector separation: 206.7 inches

secondary-corrector separation: 12.5 inches