Transcript Stellar Evolution

Question of the Day
Question: What topics do you need to review
the most before Friday’s test?
Answer: … … …
p. 551, # 2 - 7
2.
Which of the following is a possible age of the universe, according to the
big bang theory?
a. 4.6 million years
c. 4.6 billion years
b. 15 million years
d. 15 billion years
3. A pattern of stars as seen from Earth is called a ___________.
a. galaxy
c. Milky Way
b. nebula
d. constellation
4. By studying starlight, astronomers may learn which of the following
things about stars?
a. the elements that compose the star
b. the surface temperature of the star
c. the speed of the star relative to Earth
d. all of the above
p. 551, # 2 - 7
5.
The core of a star that remains after a supernova may be any of the
following except ___________.
a. a black hole
c. a red giant
b. a neutron star
d. a pulsar
6. The shape of the orbit of the Earth is _____________.
a. a circle
c. an arc
b. an ellipse
d. a sphere
7. The only outer planet that is not a gas giant is ____________.
a. Jupiter
c. Neptune
b. Saturn
d. Pluto
Galaxy Classification

Hubbles systems divides galaxies into
three basic catagories
Elliptical Galaxies
Spiral Galaxies
Irregular Galaxies
(basically galaxies that don’t
look elliptical or spiral)
Milky Way Galaxy
Our Galaxy
 Large Spiral Galaxy
 100,000 light years across
 1000 light years thick

Artist’s
Conception
The Milky Way from
Earth
Modifications to Hubble’s System
Hubble’s system only based on
appearance
 Now we know there are other differences
 Elliptical Galaxies: mostly old stars, very
little gas and dust
 Spiral Galaxies: mixture of young and old
stars, lots of gas & dust so new stars
forming
 Irregular Galaxies: mostly young stars
