HET镜面由多少块拼成？

天文学新概论上说90块，晓军姜的课件上说91块，哪个对呀？
差异是不是出在中间那个口上？

去HET网页上查第一手资料不就结了(晓军姜的是对的)
http://hydra.as.utexas.edu/?a=help&h=18

The primary mirror is composed of 91 segments, each hexagonal in shape and 1 meter across the flats. They form a large spherical surface having a radius of curvature of 26.164 meters. Each segment is positioned under computer control to yield a hexagonal primary mirror 11 meters in diameter with an area of 77.6 square meters.

晓军姜老师也让我上官网查~~~我这里上国际网不大方便……
多谢！

也就是说CCD放在焦面上了？不用反回来穿个洞~~

难道你们还考这个？太过分了吧。。

确实用上了……
让写出几个望远镜和简介，我就把这个写上了~~~