What kind of stars live forever

The more massive stars can fuse carbon into even heavier elements, which is where most of the heavy elements in the universe are made.

Throughout this whole process is that battle between gravity and gas pressure, known as equilibrium. Stars live out the majority of their lives in a phase termed as the Main Sequence. Once achieving nuclear fusion, stars radiate shine energy into space. The star slowly contracts over billions of years to compensate for the heat and light energy lost. The temperature at the center of the star slowly rises over time because the star radiates away energy, but it is also slowly contracting.

This battle between gravity pulling in and gas pressure pushing out will go on over the entire life span of the star. This activity shows what happens to different size stars at the beginning of their life cycles. A Matter of Mass. What determines how long you will live? Go Paperless with Digital. John Graham, an astronomer at the Carnegie Institution of Washington, explains.

Get smart. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber? Create Account See Subscription Options. Continue reading with a Scientific American subscription. The least massive stars will live the longest, while the most massive stars in the Universe will use their fuel up in a few million years and end in a spectacular supernova explosion.

So, how long do stars last? There are factors that will define how long a star will survive; how quickly they burn through the hydrogen fuel in their cores, and whether they have any way to keep the fuel in their core mixed up. Our own Sun has three distinct layers, the core, where nuclear fusion takes place, the radiative zone, where photons are emitted and then absorbed by atoms in the star.

The final zone is the convective zone. In this region, hot gas from the edge of the radiative zone is carried upwards to the surface of the star in columns of hot plasma. The largest possible stars probably have times the mass of the Sun; for example, the monster Eta Carinae located about 8, light years from here.

Fusion reactions release large amounts of energy -- up to 10 million times more than that produced by chemical combustion. The life of most stars follows a predictable pattern; they form initially from pockets of hydrogen and other elements in interstellar space.

If enough gas is present, gravitational forces pull the material into a roughly spherical shape, and the interior becomes denser due to pressure from the outside layers. With enough pressure, the hydrogen fuses, and the star shines.

Millions to billions of years later, the star runs out of hydrogen and fuses helium, followed by other elements. In time, white dwarfs and neutron stars cool, becoming dark objects. Chicago native John Papiewski has a physics degree and has been writing since He has contributed to "Foresight Update," a nanotechnology newsletter from the Foresight Institute.