4. What constellation is13 _ 4 13?

Aries. Constellations were introduced into China from the west, and the constellations adopted the international legislative Gregorian calendar, so the constellations were calculated according to the Gregorian calendar. Aries is the first house of the zodiac, which is located in the east of Pisces and the west of Taurus. April 13 belongs to this range, so it belongs to Aries.