Figure 18-27: R I V U X G
The Canis Major R1 Association These luminous arcs of gas are studded with numerous young stars. Both the luminous arcs and the young stars within can be traced to the same source—a supernova explosion. The shock wave from the supernova explosion is exciting the gas and making it glow; the same shock wave also compresses the interstellar medium through which it passes, triggering star formation.
(Davide De Martin)