Questions About Stars and out Planets?

Question

1What is a Star?
2What makes stars shine?
3How does Nuclear fusion produce energy?
4About how old are stars?
5How is a stars color related to its temerature?
6What is the difference between apparent magbitude and absoloute magnitude?
* Please help me with theese questions and any websites that can help me on more questions about stars! Thank you!*

Answer 1

www.wikipedia.org

It's all there.

Answer 2

1What is a Star?
A self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures.

2What makes stars shine?
The light emmited by stars make tem shine.

3How does Nuclear fusion produce energy?
The hydrogen atoms in the star combine to form heavier molecules like helium and during this process some mass gets converted to energy releasing lots of heat.

4About how old are stars?
All the stars are not created at the same time. Some star are very old and some are new and some may form in the future. We dont know when the first star appeared in the sky.

5How is a stars color related to its temerature?
http://www.enchantedlearning.com/subjects/astronomy/stars/startypes.shtml

Answer 3

1&2- A star is a massive ball of gas, primarily hydrogen and helium. The gravity of the star causes a high enough pressure inside the star to fuse hydrogen atoms together into helium, which causes the release of large amounts of energy in the form of radiation.

3- In lighter atoms, nuclear fusion releases energy because the force that holds 2 hydrogen atoms together is greater than the force that holds 1 helium atom together, so it creates extr energy when those atoms are combined. Atoms of iron and heavier actually absorb energy when they are fused together, but iron isn't usually present in a star until it is on it's final death throes.

4- The oldest stars are nearly as old as the universe itself, about 13.7 billion years. Stars last as long as they can fuse atoms to create energy. The larger the star is, the faster it exhausts all of it's hydrogen. The smallest stars can last for billions of years, so long that none of them have actually died yet. The largest stars can exhaust their hydrogen in a few million years, converting it all to helium. Eventually they fuse all of their helium into carbon, then lithium, then iron. Since iron can't be fused the star collapses since the outward pressure caused by the radiation is decreased, compacting it into such a small space that the atoms themselves fuse, the electrons and protons becoming neutrons. The star explodes, and what is left is a super-concentrated ball of neutrons. This is called a supernova. Our sun is about 5 billion years old and will last about another 5 billion years, as it is a medium sized star.

5- The hotter temperatures create higher frequencies of light. This begins as infrared radiation, which is why infrared cameras can see heat sources at night, such as animals, as glowing. Something as hot as a star produces frequencies in the visible range, such as red and yellow. It's not a pure frequency, it's several frequencies in unison, which is why a fairly hot star is seen as white instead of green. The radiation produced comes from all areas of the visible spectrum. A very hot star will show as blue because it's producing more green, blue, and violet light than red, orange, and yellow.

6- Apparent magnitude is the magnitude (brightness) as viewed from Earth. Absolute magnitude is the magnitude as viewed from a set distance from that star. For example, if you hold a candle flame at arms length at night, it will appear brighter than any of the stars, so the apparent magnitude of the candle is higher than the apparent magnitude of any given star. If you held any of those stars at arms length (hehe...) it would certainly be brighter than the candle, so the absolute magnitude of the candle is much lower than that of any of the stars.

Answer 4

Just google astronomy stars, star fusion, or something like it and you'll get plenty of reference material.

Answer 5

Hertzsprung-Russell diagram. Read up on that.