Western astrology is known as the Tropical system, while Indian astrology is the Sidereal system. Tropical (Western): Anchored to equinoxes (0° Aries = March 21 and 0° Libra = Sep 21)/ Sidereal (Indian): Uses same 12 Signs (Rashi) + 27 Nakshatras, but controversially tied to star positions. in Indian astrology (which includes extra star markers called Nakshatras), the zodiac signs are still 30° slices tied to the Sun’s path—not the uneven star patterns.