What key structural difference exists between the Sagittarius Dwarf Galaxy (Sgr Dwarf) and Sagittarius A* (Sgr A*)?

The Sgr Dwarf is a satellite galaxy composed of stars and gas, while Sgr A* is a Supermassive Black Hole (SMBH).

A significant point of potential confusion involves distinguishing between the two major objects associated with the name Sagittarius. Sagittarius A* (Sgr A*) is definitively identified as the Supermassive Black Hole located at the absolute center, or core, of the Milky Way galaxy, possessing a mass equivalent to millions of suns. In contrast, the Sagittarius Dwarf Galaxy (Sgr Dwarf) is classified as a satellite dwarf spheroidal galaxy. It is much smaller, consisting primarily of stars and gas, and is currently traversing through, rather than residing at the center of, the Milky Way's disk. The formation theory hinges on the movement of the dwarf galaxy, not the stable central mass of Sgr A*.