Cassegrainian telescope
Newtonian telescope
OAO
OSO
astronomical observatory
astronomical telescope
cheval glass
coelostat
concave mirror
convex mirror
coronagraph
coronograph
distorting mirror
glass
hand mirror
heliostat
lieberkühn
looking glass
mirror
observatory
orrery
pier glass
planetarium
radar telescope
radio observatory
radio telescope
rear-view mirror
refractor
reverberator
seeing glass
shaving mirror
spectrograph
spectroheliograph
spectrohelioscope
spectroscope
speculum
telescope
window mirror
bulb
chandelier
disk
heater
lens
nozzle
plaque
tripod
Hector
Rector
Schechter
collector
connecter
connector
defector
detector
director
erector
hector
injector
inspector
lecter
lector
nectar
objector
projector
protector
rector
sector
specter
spectre
vector