Astrology Glossary · Aspects
Orb
The forgiveness window for an aspect. A conjunction at exactly 0 degrees is rare; one within 3 degrees is still a conjunction. AIstra uses a 3-degree orb for daily forecasts so aspects are precise without being nitpicky.
An orb is the tolerance window astrologers use to decide whether an aspect counts. A conjunction at exactly 0° between two planets is rare; one at 2°57' is also a conjunction, behaving almost identically. Where you draw the line is the orb.
Different schools use different orbs. Classical Western astrology often allowed 8 to 10° for major aspects; modern hot-aspect astrology tightens this to 1 to 3° for daily-forecast precision. Wider orbs catch more signals but include weaker ones.
AIstra uses a 3° orb for daily-horoscope writing. That is tight enough to make every mentioned aspect actually felt, loose enough to not miss aspects that culminate slightly before or after midnight. When a forecast says "Venus and Mars are in trine," they are within 3° of the exact 120° angle.