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A
p
p
e
n
d
i
x
B
-
G
l
A
p
p
e
n
d
i
x
B
-
G
l
A-
Absolute ma
gnitude
Airy disk
Alt-Azimuth Mounting
Altitude
Aperture
Apparent Magnitude
Arcminute
Arcsecond
Asterism
Asteroid
Astrology
Astronomical unit (AU)
Aurora
Azimuth
B -
Binary Stars
C -
Celestial Equa
tor
Celestial pole
Celestial
Sphere
Collimation
D -
D
eclination (DEC)
E -
Ecliptic
Equatorial mount
o
s
s
a
r
y
o
f
T
e
r
m
s
o
s
s
a
r
y
o
f
T
e
r
m
s
The apparent magnitude that a sta
parsecs, or 32.6 light-years. The a
would just be visible on Earth on
The apparent size of a star's disk
be focused perfectly, 84 per cent
a system of surrounding rings.
A telescope mounting using two
Altitude and Azimuth.
In astronomy, the altitude of a celestial object is its Angular Distance above or below the celestial
horizon.
the d
iameter of a telescope's prim
telescope's light-gathering power
A measure of
the relative brightn
Earth.
A u
nit of angular size equal to 1/6
A u
nit of angular size equal to 1/3
A s
mall unofficial grouping of stars in the night sky.
A small, rocky body that orbits a
The pseudoscientific belief that th
affairs; astrology has nothing in common with astronomy
The distanc
e between the Earth and the Sun. It is equal to 149,597,900 km., usually rounded off to
150,000,000
km.
The emission of light when charg
molecules in a planet's upper atmosphere.
The angular distance of an object
the astronomical meridian (the ve
south points on the horizon) and the vertical line containing the celestial body whose position is to
be measured.
.
Binary (Double) stars are pairs o
around a common Center of Ma
called a multiple system. It is be
multiple systems. Systems with
called visual binaries or visual m
actually our n
earest example of a multiple star system, it consists of three stars, two very similar to
our Sun an
d one dim, small, red star orbiting around one another.
The projection of the Earth's equ
hemispheres.
The imaginary projection of Ear
An imaginary sphere surroundin
The act of putting a telescope's o
The angular distance of a celestial body north or south of the celestial equator. It may be said to
correspond to latitude on the surface of the Earth.
The projection of the Earth's orbit on to the celestial sphere. It may also be defined as "the apparent
yearly path of the Sun against the stars".
A telescope mounting in which the instrument is set upon an axis which is parallel to the axis of the
Earth; the angle of the axis must be equal to the observer's latitude.
r would have if it w
ere observed from a standard distance of 10
bsolute magnitude o
f the Sun is 4.8. at a distance of 10 parsecs, it
a clear m
oonless night away from surface light.
produced even by
a perfect optical system. Since the star can never
of the l
ight will concen
trate into a single disk, and 16 per cent into
independent rotation axis allo
ary lens or mirro
r; the larger the aperture, the greater the
.
ess of a star or oth
er celestial object as perceived by an observer on
0 of a degree.
,600 of a
d
egree (or 1/60 of an arcminute).
star.
e position
s of stars and planets exert an influence on human
ed particles from the
solar wind slams into and excites atoms and
eastwards alon
g the horizon, measured from due north, between
rtical line passing through the
f stars that, because of their mutual gravitational attraction, orbit
ss. If a group of three or more stars revolve around one another,
lieved that approximately 50 percent of all sta
individual components that can be seen separately b
ultiples. The nearest "star" to our solar system, Alpha Cen
ator on to the celestial sphere. It divides the sk
th's rotational axis north or south pole onto the celestial sphere
g the Earth, concentric with the Eart
ptics into perfect alignment.
42
wing movement of the instrument in
center of the sky and the north and
rs belong to binary or
y a telescope are
y into two equal
h's center.
it is
tauri, is
.
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