Space is filled with countless, marvelous stars. For many centuries, scientists have worked to uncover the many details that make stars so appealing.
A star’s life has multiple stages and lasts hundreds of millions of years. The life of a star starts with a nebula, which is a large cloud of hydrogen, helium, and microscopic dust. When a shock wave goes through a nebula following the explosion of a nearby star, a protostar forms in the center of the nebula. The protostar gets hotter and hotter until a new star is created.
Stars differ in size, but all of them will eventually become planetary nebulas, a stage at which the stars slowly lose their outer layers and die. A massive star can live for hundreds of millions of years, while a small star can live up to a billion years.
For years, scientists have studied the diameter, age, mass, and "natural resonance" of stars. In regards to natural resonance, think of a musical instrument; lower sounds come from a bass, which is bigger, and higher sounds come from a violin, which is smaller. Scientists use technical instruments to pick up on a star's vibrations, which can reveal their age, masses, and diameters.
When a heavy star burns through all of its hydrogen and explodes into a supernova, its core gets smaller and smaller. Then gravity affects the star and is so strong, that this process ultimately creates a black hole.
Even though stars might not appear alive to those of us gazing at them from Earth, they actually live for many years and eventually die just like all living creatures do.
[Source: Stars and Planets, BBC.com]