1. Main Sequence Star
Red Giant
Planetary Nebula
White Dwarf
Star Formation Nebula
Protostar
Neutron Star
Massive Star
Red Super Giant
Black Hole
SuperNova

2. STARS ARE CLASSIFIED ACCORDING TO THEIR:
Size
Temperature
Color
Brightness

4. GALAXY- a group of stars, dust, gas, and other objects held together by gravitational forces.

5. Our fastest spacecraft travels 30 km/s; it can travel from Los Angeles to San Francisco in 25 seconds. At this speed, it would take 40,000 years to travel to the nearest star (Alpha Centauri- 4.3 light years), and it would take 10 billion years to travel across our galaxy.

6. LIGHT YEAR- The distance light travels in one year
LIGHT YEAR- The distance light travels in one year. This is equivalent to light traveling at 300,000 km/s, or 186,000 miles/s.
ASTRONOMICAL UNIT (AU)- The distance between the Earth and the Sun (150 million km).

7. SPIRAL GALAXY
Consist of a dense area in center surrounded by spiraling arms.

9. BARRED SPIRAL GALAXY
Have a bar-shaped structure in center.

10. ELLIPTICAL GALAXY
Looks like the central portion of a spiral galaxy without the arms.

11. LENTICULAR GALAXY
Lens-shaped with a smooth, even distribution of stars and no central, denser area.

12. IRREGULAR GALAXY
Peculiar shapes and do not appear to rotate like those galaxies of other shapes.

13. NEBULA
A huge cloud of dust & gas from which stars form.

14. ORION NEBULA

15. SUPERNOVA
The explosion of a very large star.

18. CYGNUS LOOP- SUPERNOVA

30. CONSTELLATION- a pattern of stars in the sky.