Stars can be classified by their temperature as hot blue stars around 30,000 degrees, cool red stars around 2,500 degrees, or yellow stars like our sun around 6,000 degrees. Constellations like Orion can be identified by patterns of brighter stars. The brightness of stars is measured by their apparent and absolute magnitudes, with lower numbers indicating brighter stars. A nebula is a cloud where stars are born, and the Eagle Nebula is an example. Stellar evolution progresses from protostars to main sequence stars like our sun fusing hydrogen, then to giants and supergiants fusing helium, eventually leaving behind planetary nebulae and forming white dwarfs, or in massive stars, supernovae leading to neutron stars or

1. Stars

3. Constellation Orion

6. Big Dipper

8. Eagle Nebula

13. Sun

20. All visuals are from : “ Astronomy Picture of the Day” from NASA found at: http://antwrp.gsfc.nasa.gov/apod/