1. Constellations
The Night Sky

2. A couple of things to know before we start…
Polaris (North Star): positioned almost directly over Earth’s north pole.
Light-year: unit representing the distance light travels in one year – about 9.5 trillion km – about 186,000 miles per second.
Stars in constellations appear close together, but they are often light-years apart.

3. A couple of things to know before we start…
Absolute Magnitude vs. Apparent Magnitude
Absolute Magnitude is a measure of the amount of light the star gives off. (How bright it is)
Apparent Magnitude is a measure of the amount of light received on Earth. (How bright it looks to us)

4. Modern astronomy divides the sky into 88 constellations.

5. A couple of things to know before we start…
Circumpolar Constellations: Constellations that appear to rotate around Polaris.
These constellations appear to move because Earth is moving.
Circumpolar constellations are visible all year long.
Cassiopeia
Ursa Major
Ursa Minor
Draco
Cepheus

6. Orion

7. Orion

8. Orion
Betelgeuse: A red supergiant, 9th brightest star in the night sky, 2nd brightest in Orion, appears red/orange in color.
Rigel: a blue white star, 7th brightest star in the night sky, brightest in Orion. 863 light years from Earth.

9. Orion
Orion Nebula: one of the brightest nebulas visible to the naked eye.
Estimated 24 light years across.
Closest region of star formation to Earth.

10. Cassiopeia

11. Cassiopeia

12. Cassiopeia One of the original 48 constellations listed by Ptolemy.
Visible from September to early November.
Cassiopeia is home to “Tycho’s Supernova”.
Happened in November of 1572
Was visible during the day
Could be seen with the naked eye for 2 years

13. Cassiopeia

14. Ursa Major: The Great Bear

15. Ursa Major: The Great Bear

16. Ursa Major: The Great Bear
One of the original 48 constellations listed by Ptolemy.
3rd largest constellation in the sky.
Home to several bright galaxies

17. Cygnus

18. Cygnus

19. Cygnus One of the original 48 constellations listed by Ptolemy.
Deneb is one of the brightest stars in the night sky. (Brightest in Cygnus)
Believed to contain a black hole. Discovered in 1964 with one of the strongest x-ray sources seen from Earth.

20. Scorpius

21. Scorpius

22. Scorpius
Antares is the brightest star in Scorpius. 16th brightest in the night sky.
Scorpius contains the Butterfly/Bug nebula.
More than 2 light years across.