ASTRONOMY 5

THIRD HOUR SESSION H

NAME

KEY-H

 

 

 

 

 

ACTIVITY: More on the HR Diagram

DATE

 

ID#

 

1. Where on the HR diagram do you plot stars that are burning hydrogen in their cores?

Main sequence

2. What are the names (and if relevant, luminosity classes) for stars in regions ____ Region2, Region 3______?

Red giants

Supergiants

3. What is the approximate temperature and luminosity of a star at _Region 6_?

T: 20,000 K

L: 103 Lsun

4. Which star is ____More luminous_____? A star with spectral class B2 V_ or a star with spectral class __B7 V__?

B2 V

5. At which point or area on the HR diagram (i.e., Region 1, Region 2, etc.) would you plot the Sun?

Region 8

6. Use Starry Nights to determine the point or area on the HR diagram (i.e., Region 1, Region 2 etc) you would plot _____Spica________ and _Betelgeuse___?

Region 6: (20396 K 4870 Lsun)

Region 2 (3488 K, 305089 Lsun)

 

7. Use the data table (next page) to correctly place the spectral types OBAFGKM at the bottom of the HR diagram.

8. Similarly, use the data table to label the main sequence with the masses of the stars at each spectral type. (Note: masses are approximate.)

9. Approximately what luminosity is a __3000 K___ main sequence star? What about a supergiant star at the same temperature?

10-3 Lsun

105 Lsun


10. How many times more luminous is a ___B5 V_____ star than the Sun? How many times more massive is it?

1000

10

11. Which would you expect to live on the main sequence longer? The Sun or the star in question #10?

The Sun

 

O

B

A

F

G

K

M

35000K

20000K

9000K

7000K

5800K

4500K

3200K

60M8

10M8

2M8

1.4M8

1M8

0.7M8

0.3M8

Q8) 0.3 Msun

 

Q8) 0.7 Msun

 

Q8) 1 Msun

 

Q8) 2 Msun

 

Q8) 10 Msun

 

Q8) 60 Msun

 

Q8) 1.4 Msun

 

Q7) O B A F G K M