Assertion: reflecting telescope's mirror | /r/AtLocation | place
Facets:
value: by thin vanes
type: OTHER
Source sentences:
text: Held in place by thin vanes called the “spider” assembly, this secondary mirror captured the refocused light path in a non-magnified way and was aimed at a porthole on the top side of the optical tube.
text: The diagonal mirror is held in place with a thin four-vane spider.