Figure 23-20: The Canis Major Dwarf Discovered in 2003, this dwarf elliptical galaxy is actually slightly closer to Earth than is the center of the Milky Way Galaxy. This illustration shows the stream of material left behind by the Canis Major Dwarf as it orbits the Milky Way. This material is torn away by the Milky Way’s tidal forces (see Section 4-8).

(R. Ibata et al., Observatoire de Strasbourg/Université Louis Pasteur; 2MASS; and NASA)