Assertion: newtonian telescope's mirror | /r/HasProperty | made for enhanced thermal stability
Facets:
value: from bk7 optical glass
type: OTHER
Source sentences:
text: The precisely figured 6" f/4 primary mirror is made from BK7 optical glass for enhanced thermal stability.
text: The precisely figured 10" f/5 primary mirror is made from BK7 optical glass for enhanced thermal stability.
text: The precisely figured 10" f/4 primary mirror is made from BK7 optical glass for enhanced thermal stability.
text: The precisely figured 8" f/5 primary mirror is made from BK7 optical glass for enhanced thermal stability.