Lecture 3

Question 1

How many stars are in the milky way galaxy?

Answer 1

200 million-250 billion

Question 2

What are some of the components of the milky way?

Answer 2

Planets gravitating around stars, nebulae, interstellar dust, solar systems.

Question 3

What do things gravitate around in the milky way?

Answer 3

The centre of the galaxy-consists of closely spaced stars and dense dust.

Question 4

What is the diameter of the milky way and it’s mass?

Answer 4

80 000 light years, and 750 billion times the mass of the sun

Question 5

What are the four arms of the milky way galaxy?

Answer 5

Perseus, Cygnus-Orion, Sagittarius and Centaurus

Question 6

What is the “local group?”

Answer 6

The group of galaxies in relatively close proximity to us-ours is part of the Virgo Superchain

Question 7

Who discovered the existence of red and blue shifted stars?

Answer 7

Vesto Stipher

Question 8

What does it mean that a star is blue shifted/red shifted?

Answer 8

Blue shifted- the very few galaxies that are moving towards us
Red-shifted- galaxies moving away from us

Question 9

How did we find out the existence of red and blue shifted stars?

Answer 9

Once we invented telescopes that were able to see infrared waves.

Question 10

What did Edwin Hubble discover?

Answer 10

The farther away a galaxy is, the faster it is receding. This proves that the Universe is EXPANDING

Question 11

How can we calculate the universe’s age?

Answer 11

Using it’s rate of expansion.

Question 12

When did the process of universe expansion begin?

Answer 12

13.7-13.8 billion years ago (before this, it’s mass was concentrated into a very small space)

Question 13

What is the Big Bang Theory?

Answer 13

Theory that explains the initiation of universe expansion.

Question 14

Which two space craft gave experimental confirmation of the Big Bang?

Answer 14

COBE and WMAP

Question 15

What did COBE (Cosmic Background Explorer) measure in 1992?

Answer 15

Discrete temperature fluctuations in the deepest regions of space.

Question 16

What did WMAP measure in 2002?

Answer 16

Plotted the oldest light in the universe.

Question 17

What are the Nebulae?

Answer 17

Concentrations of interstellar gas and dust.

Question 18

How are Nebulae formed? (3 Ways)

Answer 18

1) Concentration of small sized material
2) Explosion of a star or other celestial body
3) Collision between 2 or (rarely) more celestial bodies

Question 19

What is the Eagle Nebulae?

Answer 19

The most spectacular nebula we know of- regarded as a typical example of “the birthplace of stars”

Question 20

What does the Eagle Nebulae consist of?

Answer 20

Dust, gases (hydrogen and helium), and vapors which are referred to as “interstellar fog”

Question 21

What are stars?

Answer 21

Massive celestial bodies consisting of ionized gas (hydrogen and helium)

Question 22

What is gravitational contraction?

Answer 22

Due to a stars mass being so big, they are constantly in danger of shrinking.

Question 23

What are some of the stars that are smaller than the sun?

Answer 23

Sirius B, Proxima and Centauri

Question 24

What are some stars that are bigger than the sun?

Answer 24

Rigel and Beetle Juice