These are the most frequently used words in another edition of this book.
aperture
apparent
appear
area
astronomical
axis
between
binary
bright
brightness
called
celestial
centre
change
chart
clouds
cluster
colour
comets
date
day
dec
diameter
disk
distance
double
earth
eclipses
effect
example
exposure
eye
eyepiece
features
field
figure
film
filters
fixed
galaxy
given
gives
globular
hour
image
jupiter
km
known
large
latitude
light
longitude
mag
magnitude
mars
may
mean
moon
motion
nebula
north
number
object
observations
observer
open
orbit
period
planet
planetary
pole
position
range
ring
satellites
second
see
seen
should
show
sky
small
solar
south
spiral
spots
stars
sun
surface
system
table
telescope
time
two
type
used
usually
variable
visible
years