How Do Stars Form?

1. How Do Stars Form? Galaxies of Stars

2. The Sun • By far the nearest star to earth. • A star is a large self-luminous body in space that creates its own radiant energy. • It gets its energy from nuclear fusion • During fusion under conditions of extreme heat and pressure in the star, the nuclei of two hydrogen atoms join to form a single helium nucleus.

3. The Sun • Nuclear fusion reaction produces a huge amount of energy • Fusion reaction in larger stars such as red giants produce heavier elements such as carbon, oxygen, and iron • The formation of the heaviest natural elements requires the conditions found only in massive stellar explosions.

4. Orion Nubula • A nubula (from Latin: "cloud";pl. nebulaeor nebulas) is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases. • The Orion Nebula (also known as Messier 42, or M42) is a diffuse nebula situated southof Orion's Belt. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of 1,344 ± 20 light years[3][6] and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light years across.

5. The Life Cycle of a Star

6. Betelgeuse

7. Stellar Ejection

8. Stellar Mass Ejection • Is a phenomenon observed in some massive stars causing the ejection of a large portion of the star's mass.

10. Betelgeuse Rigel

12. RIGEL

13. Tycho Supernova