Possible Clues:

• Astronomical bearing
• Angle measured by an astrolabe
• Astronomy angle
• Bearing component unknown in train, initially used too hard
• (In astronomy and navigation) angle of a bearing measured clockwise from North
• Horizontal angle of a bearing
• Angle between vertical plane containing a celestial body and plane of the meridian
• Angle presented by extreme characters — I say nothing must be forbidden
• Horizontal angle of bearing
• 29 in astronomy