This note is to clarify the status of the new secondary for the 3.5m telescope. My appologies if this information was not widely circulated earlier. On September 18, 1995, Hextek completed fabrication of a blank for the 3.5m telescope replacement secondary. In early October '95, a detailed inspection revealed that, although the faceplate had some departure from sphericity, which would ultimately lead to nonuniformity in faceplate thickness when finished, the part was better than the original 33" blank and was acceptable. In mid-January '96, Hextek was given the go-ahead to do further work on the blank to prepare it for final optics figuring, which included: - The overall faceplate and backplate diameters were ground to 32.90" +/- 0.02". - The center back plate was bored to 2.16" diameter, concentric with the faceplate to +/- 0.1". - The three support holes in the back plate (120deg apart on a radius of 8.66" from the center) were bored to 2.16" diameter. - The remaining cell holes were enlarged for ventilation. - The front surface was fine ground to a radius of curvature of 125.342" +/- 0.01" over 12" spatial scales. The surface figure is better than 1.5 fringes (650 nm) over 7" spatial scales. These efforts were completed on July 11, 1996 and the secondary was shipped to JHU. -pw APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 159 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO