 As a big star is born, it produces powerful winds. They push material away from the star, forming a bubble that squeezes the surrounding gas and dust. If this material is squeezed tightly enough, it collapses to form a new star. The newborn, in turn, produces its own bubble, triggering the birth of more stars, and so on. Because Nessie is so long, it'll take millions of years for that process to play out.