celestial
sphere
circumpolar
constellations
dark
cloud constellations
draconic
month
ecliptic
equinoxes
(March and September)
helical
rising and setting
intercalation
Julian
calendar
lunar
calendar
lunar
standstill
lunistice
Metonic
cycle
nadir
nodes
retrograde
motion
saros
cycle
sidereal
month
solar
calendar
solstices
(June and December)
synodic
month
synodic
period of Venus (“Venus Year”)
tropics
(Cancer and Capricorn)
zenith
zenith
passage
zodiac
Aubrey
Holes
Heel
Stone
henge
Mesoamerica
sexagesimal
system
vigesimal
system
(From
Seeing and Believing)
aberration
of light
absolute
magnitude
absorption
spectrum
brightness
camera
obscura
cepheid
variable
continuous
spectrum
diffraction
grating
emission
spectrum
HR
diagram
island
universe
light
year
luminosity
nebula
parallax
parsec
proper
motion
reflecting
telescope
refracting
telescope
spectroscope
Stefan-Boltzman
Law
Wien’s
Law
zone
of avoidance