User’s Guide to the Sky: Patterns and Cycles

1. User’s Guide to the Sky: Patterns and Cycles Stars Chapter 2 Section 1 (pages 10-14) See your notes handout for the notes that go with these images.

2. Space is nearly empty

3. Motions in the sky are cyclical

4. Stars in the sky – there are billions • Some have been named, most have not.

5. Stars are grouped into constellations to tell of ancient myths and heroes.

6. Astronomers measure the brightness of stars using the magnitude scale.

7. Apparent magnitude scale • How bright a star appears with the human eye from Earth.

8. The Scale dates back to ancient times • Hipparchus (190-120 BCE), a Greek astronomer is credited with compiling the first star catalog, and there is evidence to suggest that he used the magnitude system in his catalog. • Claudius Ptolemy (~140 CE), an Egyptian-Greek astronomer also created a star catalog, and he

9. We will look at specific constellations and be able to locate them in the sky.