Quadrant is one of eight divisions of the celestial sphere, four in both northern and southern hemispheres. Quadrants occupy 6 hours of right ascensions. For northern quadrants, it is written 'NQ' while for southern quadrants, it is written 'SQ'. These are followed by numbers from 1 to 4. Quadrants can also be named based on the season when the sun crosses that quadrant and merosimer based on the range of right ascension.
|First||0–6||Spring quadrant||Afternove quadrant|
|Second||6–12||Summer quadrant||Forenoon quadrant|
|Third||12–18||Autumn quadrant||Afternoon quadrant|
|Fourth||18–24||Winter quadrant||Forenove quadrant|
Quadrants of constellations and caelregios are specified based on their midpoints. For example, the Orion constellation is located in the first quadrant of the northern hemisphere, written as NQ1. The Simianus caelregio is located in the third quadrant of the southern hemisphere, written as SQ3.