Parts of a Star
- The inner part of a star is called the core. It is the hottest part of a star and it is where nuclear fusion takes place to power the star.
- The middle part of the star is called the radiative zone. It is where all the radiation is moving outwards from the core.
- Beneath the surface is the convection zone. The cooler areas are sinking down as the hotter areas are moving upward and it creates a cycle of circulating air.
- The surface of the star is called the photosphere. It isn't really a surface like our Earth's surface.
- Right off the surface is called the chromosphere. It looks reddish because of all the hydrogen found there.
- A prominence is when a large loop shaped gaseous feature extending outward from the sun. Can last from an hour to up to a year.
- A solar flare is when a part of the sun brightens up because of an energy release.
- The corona is a type of plasma atmosphere extending far out into space.
Polaris is a little off of the main sequence section of the HR Diagram. That means that it is just starting its death phases. It is expanding into the supergiant region. When a star starts to die, its running out of hydrogen. A star uses hydrogen and it fuses it to form helium. After that, the star doesn't have enough heat or mass to fuse helium into carbon. Since it has no more fuel, the gravity takes over and crushes the core. When something gets compacted, it heats up. Then the core gets hot enough to fuse helium into carbon. This makes a star expand then get smaller, then expand again and get smaller again. Polaris is in its stage of expanding.
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