These are the most frequently used words in this book.
100
1010
109
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
absorption
aj
al
apj
cambridge
clusters
cm
co
constant
continued
data
days
density
distance
earth
edited
electron
emission
energy
et
field
figure
flux
function
galactic
galaxies
given
gives
ii
iii
kev
km
level
lines
log
luminosity
magnetic
magnitude
mass
may
mean
mnras
models
name
new
ngc
notes
number
optical
per
period
phys
press
radiation
radio
range
references
section
see
si
sky
sn
solar
source
spectra
spectral
spectrum
stars
stellar
surface
survey
system
table
temperature
time
total
type
units
university
values
velocity
wavelength
year