In galactic coordinates, what longitude marks the Galactic Center?

In galactic coordinates, 0 degrees longitude marks the Galactic Center.

Galactic longitude, written as l, measures angular position eastward along the Milky Way’s galactic equator. Astronomers define its zero point in the direction of the Galactic Center, so the center is assigned l = 0°. Longitude then increases around the sky through 90°, 180°, and 270° before returning to 360°, which is equivalent to 0°.

The International Astronomical Union established the modern galactic coordinate system in 1958, using radio observations of the Milky Way’s neutral hydrogen. The zero direction is associated with Sagittarius A, the complex of radio sources at the Galaxy’s center, including the compact source Sagittarius A*.

The coordinate origin is a defined reference direction, not a claim that Earth sits at the center of the Galaxy. Also, the physical radio source Sagittarius A* has a measured position extremely close to, but not mathematically identical with, the idealized coordinate zero. The opposite direction, the galactic anticenter, is 180° longitude and lies toward Auriga.