Astronomy 128              Homework         5                                  Printable Version

 

 

1)       Identify the location and  process that forms each of the following types of element.

Locations might be , high mass stars, low mass stars, supernovae etc. Effects of the Big Bang are identified separately because you have not studied it yet)

Element(s)

Location where formed

Process

(name of the nuclear process)

Hydrogen

Big Bang, before stars

xxxxxxxxxxxxxxxxxx

Helium

______ and Big Bang

 

Carbon 12

 

 

Oxygen 16

 

 

Sulfur 32

 

 

Iron 56

 

 

Cobalt 60, Bismuth 209

 

 

Uranium 238, Plutonium 242

 

 

Bismuth 209

 

 

 

2)       What causes the radiation from a pulsar to vary?

3)       How do we know that a pulsar is small?

4)       Which is has a bigger radius, a neutron star, a black hole  with mass  of a couple of solar masses or a white dwarf?

5)       What is the evidence that gamma ray pulses are parts of distant galaxies?

 

6)       Why is it harder to find the shape of our galaxy, the Milky Way, than to find the shape of an external galaxy like the Andromeda Galaxy?

 

7)       How do we find the rotation of the far side of our galaxy ?

 

8)       Which is brighter, a Cepheid variable star that pulses every 3 days or one that pulses every 15 days?                 If a Cepheid variable pulses every 10 days, how many times as bright as the Sun is it?

 

10) Where in our Galaxy would you look for the following?

a) Young, massive stars

b) Dust

c) Globular Clusters

d) Galactic Clustsrs

e) Emission nebulae

 

11) Describe the evidence that there is a massive Black Hole at the center of the Milky Way.

 

12)  What are spiral arms made of?

 

13)  What is the evidence that our Galaxy has more mass than what we can find in the stars and the gas?

14) What is a MACHO?

 

15) How do we use gravitational lensing to detect MACHO’s?