1. Horizon Coordinates
A: Azimuth. The angle measured beginning at cardinal pt. north eastward along the horizon to the base of the vertical circle of the object. Azimuth is measured in units of degrees.
h = 90o
h: Altitude. The angle measured upward from the horizon along the vertical circle of an object to the object itself. The angle is measured in degrees. Z
Vertical Circle
h = 30o
A = 270o W
A = 310o
45o = h
A = 180o N N
A = 0o S A
= 135o
h = 0o E
A = 90o

2. Celestial CoordinatesZ
R.A.: Right Ascension. The angle measured beginning at the vernal equinox eastward (counter-clockwise) along the celestial equator to the base of the hour circle of the object. R.A. is measured in units of hours, minutes and seconds.
V.E.
R.A. = 0h
HOUR CIRCLE
NCP
 = 90o (at NCP)
R.A.
= 5h W 
= 40o S N N
V.E.: Vernal Equinox. The point on the celestial equator from which Right Ascension is measured. The vernal equinox moves at the same rate as the stars (361o west every day with respect to the horizon).
 = 0o (on C.E.)
HORIZON
δ: Declination. The angle measured upward (if positive) or downward (if negative) from the celestial equator along the hour circle of an object to the object itself. The angle is measured in degrees.
CELESTIAL E
EQUATOR
SCP
 = -90o (at SCP)

3. Celestial Coordinates on a Skychart
R.A. = 7h37m
δ = 5.5o
δ = -8o
R.A. = 5h10m