What constellation is the vernal equinox?

The vernal equinox is in Aries (ecliptic 0).

What is the vernal equinox? Answer; The earth's axis rotates obliquely around the sun to the left. When the sun shines directly at the equator of the earth, it is the vernal equinox. Then the astrological house on the ecliptic corresponding to the earth (geocentric era thinks that it goes around the earth and the astrological house corresponding to the sun is Aries) is Libra, and the sun corresponds to Aries at this time. Vernal equinox's house is Aries for the sun and Libra for the earth.