Stars in the Sky

1
Stars in the Sky

• Section 3

2
Bell ringer

• What are 3 characteristics of stars?
• How does apparent magnitude differ from absolute
  magnitude?
• Based on your HR Lab, write down something you
  learned about stars.

3
Life Cycle of Stars

• All stars begin as a ball of gas and dust
• Gravity pulls in the gas and dust as a sphere
• Stars spend most of their time in the main
  sequence

4
H-R Diagram

• What is the HR Diagram?
• What does it study?
• What are the two classifying components of a HR
  Diagram?
• What else does it show?
• What type of pattern do main sequence stars
  follow?
• How do stars begin?
• What type of force forms stars?
• Where do stars spend most of their time?
• As stars age, which direction do they move?
• When a star loses its atmosphere, what is left
  behind, where are they located, and what are they
  called?

5

• Supernova-
• death of a large star by explosion
• Heavy
• Uses up their hydrogen faster than stars like the
  sun
• Heavy elements like gold, lead, and silver are
  formed by supernova explosions

6
Neutron Stars

• Very dense and heavy
• Particles of the left over supernova form a star
  without a charge and made of neutrons
• A spinning neutron star is called a pulsar

7
Black Hole

• A collapse of a super nova
• Its gravity is so powerful that light can not
  escape

8
Questions

• What information does the H-R diagram give us?
• What is a supernova?
• What is a neutron star? How does it differ from
  a pulsar?
• Are blue stars young or old? How can you tell?
• In main sequence stars, what is the relationship
  between brightness and temperature?
• In order of appearance arrange the life cycle of
  a star white dwarf, red giant, and main
  sequence star. Explain your answer.