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Educational Purposes

1. By: Arnyl Angelo B. Mendoza Characteristics of Stars Grade: 9 Section: Lilac SCIENCE

2. Stars A luminous spheroid of plasma held together by self-gravity. Large celestial bodies components of hot gases. It contain mostly Hydrogen and Helium. They emit electromagnetic radiation as light which is a product of nuclear fusion within the star. Cooler stars are red, while the hottest stars are blue-white.

3. The Sun is a typical, main sequence star. It is the nearest star to Earth. Other stars are visible to the naked eye at night; their immense distances from Earth make them appear as fixed points of light. Main sequence stars convert hydrogen into heliumin their cores, releasing a large amount of energy. When a star runs out of hydrogen in its core, fusion stops and the star increases in size up to 100 times. Example of Stars

4. COLOR A star’s color depends on its temperature. Characteristics of Stars

5. TEMPERATURE Stars with higher temperature will be brighter assuming these stars have the same sizes and distance from the Earth. Characteristics of Stars

6. Characteristics of Stars SIZE Suppose two stars are in the same distance from the Earth and have the same temperature, but one star is much larger than the other, then the larger star will be brighter than the smaller star. Super Giants are very large stars and use their hydrogen very fast and die young. They will eventually explode into a supernova or nova, and may become a black hole. They are very bright but cooler on the surface.

7. COMPOSITION Stars consist of photosphere which is an atmosphere of hot gases. The corona or the outer atmosphere of the sun consists of outflowing stream of particles called solar wind . A spectograph is the instrument used by astronomers to determine elements in stars. It spread out the light into a spectrum. Joseph Fraunhofer is a German physicist that observed the spectrum of the sun showing dark lines crossing a continuous band of colours. William Huggins and Lady Margaret Huggins found out that the same chemical elements found in the sun and planets exist in the stars. Characteristics of Stars

8. BRIGHTNESS Stars differ in their brightness and scientists call this brightness its magnitude . The closer the star, the brighter it will appear if they have the same size and same temperature. Stars of the first magnitude are the brightest stars and the dimmest stars are called stars of the sixth magnitude . Apparent brightness is star’s brightness as seen from Earth. Absolute brightness is the brightness the star would be if it were at a standard distance from Earth. Characteristics of Stars

9. Thank you 