Like a Diamond in the Sky Trivia Quiz

It takes an intense situation for a star to form. The very earliest stage of star formation is its beginnings as a solar mass within a molecular cloud in space. These vast molecular clouds, often 100 light-years wide, can contain a staggering amount of such solar masses: on average, some 6,000,000! It these solar masses that will eventually make up what we know as stars.

The gravitational collapse of the molecular cloud, made up of thousands of solar masses, is what triggers the formation of stars. The cloud and its solar masses fragment away during the gas collapse, releasing energy and thus building up heat. The increasing energy and heat make up two of stars' characteristics: pressure and heat. The buildup of these helps to form a protostar, the first real stage of a star's life.

A protostar is not quite a main-sequence star, yet no longer a generic solar mass. Forming out of the fragments created by the collapse of the molecular cloud, the protostars continue to feed on the gas and dust left from the cloud's gravitational collapse. Over time, these fragments build up and a protostar is formed.

The increasing energy powers the protostar to continue growing, pressurizing, and heating up.

From a protostar to a pre-Main Sequence star! As the protostar continues to grow, adding dust and gas and increasing in heat and pressure, it becomes a pre-Main Sequence star. A pre-Main Sequence star, which is also sometimes referred to as a PMS star, is a star that has not yet begun its nuclear fusion of hydrogen.

A PMS star is a protostar that has blown away its surroundings of dust and gas, having reached a large enough size, and then begins to contract, building up the heat and pressure necessary for it to begin nuclear fusion and thus become a Main Sequence star.

Once the PMS star has contracted enough, building up heat and pressure, it begins nuclear burning, or fusion, of hydrogen. This is what makes a star a Main Sequence star, such as the Sun. Main Sequence stars can burn for millions of years, depending on the mass of the star. For example, the Sun is approximately halfway through its predicted 10 million year Main Sequence life.

Main Sequence stars get this name from the fact that when they reach this stage, they are visible on stellar plots along a central band.

What a star will do after its supply of hydrogen dwindles depends on the star's mass. In this case, as Lucy is a high-mass star, when the hydrogen fails the core contracts and heats up hotter, generating enough heat to begin nuclear fusion of helium. However, should the star be a low-mass star, it would never be able to generate enough heat to begin fusing helium, and so it would move into a white dwarf stage.

Interestingly, because stars have been estimated to have billion and even trillion-year lifespans, most information on their later lives has been deduced rather than observed; this is because the universe is only 13.8 billion years old--not long enough for most of the universe's stars to reach end-of-life stages.

Once the massive star's supply of helium dwindles, it will have created a core of oxygen and carbon. At this point, the carbon ignites, and nuclear carbon fusion begins. The fusing of carbon, in turn, creates sodium, magnesium, and neon. These heavier elements will provide fuel for the last stages of the star's life.

A high-mass star such as this eventually runs out of its carbon supply. However, the other elements that it created while fusing carbon, such as neon, magnesium, and sodium, provide fuel at this point, where high-mass stars have enough heat to burn them. However, this burning is an unstable process and eventually leads to the star's demise.

Neon burning occurs after carbon burning, and then other elements such as silicone and oxygen. It is an unstable process for the star. At this point the core of the star expands, and after becoming unable to support its mass, it collapses. Once again, the size of the star determines what happens next; some stars will collapse into nebulae, but a star as massive as Lucy will collapse directly into a black hole.

A star such as this one with a high mass will continue collapsing after it goes supernova. This collapse creates a black hole. Predicted originally in the 18th century, although although Albert Einstein questioned whether they could actually exist, black holes are an area of space where gravity is so strong that nothing, not even light, can escape from it. Black holes grow by adding more matter into them; however, based on predictions made by Stephen Hawking, black holes may actually evaporate over billions of years. What happens to what was once a massive star then? No one yet knows.