Download THE HERTZSPRUNG-RUSSELL DIAGRAM (H

THE HERTZSPRUNG-RUSSELL DIAGRAM
(H-R DIAGRAM)
1.
NOTE: Absolute Magnitude IS THE SAME THING AS LUMINOSITY ON THE GRAPH
DEFINE: absolute magnitude (Pg. 372 if you don’t know)
2.
Look at the Hertzsprung-Russel diagram below. What does the vertical (up and down) axis represent?
__________________________
What does the horizontal (right to left) axis at the bottom represent?
_______________________________
3.
Using the H-R diag. what is the surface temperature of the sun?
_________________
4.
What is the luminosity of the sun on this diagram?
__________
5.
There are other lines (diagonal lines) shown on the graph
marked “solar radii” (radii is plural for radius) on the righthand side. These lines are used to represent the
physical size of stars on the diagram. Using the diagonal
solar radii lines, give the solar radius (size) of the sun.
___________
6.
What is the “luminosity” of the star marked “x”?
_____________
7.
What is the size (solar radii) of the star marked “Y”?
_____________
8.
Hertzsprung-Russell Diagram Interactive
A. Use the “Star Evolution on the H-R Diag.” link or go to
B. Setup: Click the “show regions” box (lower right)
C. Setup: Set the “Speed” slider to approx.
http://mrphome.net/mrp/HR_evolve.html
5 x 10^6 Y/s
Experiment: How does a stars’ mass affect how long stars live?
Hypothesis: If a star has a (circle one: greater / lesser) mass, then its life will be longer.
Independent Variable: ___________________________ (what variable will you be changing?)
Dependent Variable: ____________________________ (What variable will you be measuring?)
Procedure:
A. Using the “Mass” slider and the “Create Star” button, create 6 stars with the following masses:
DO NOT X-OUT UNTIL YOU ANSWER BOTH QUESTIONS BELOW!!
Set Mass To
1
2
5
10
30
Record Age
(Life Span)
(Wait until done)
Conclusion: What have you found out?
Question: Looking at your plots ON THE SIMULATION SCREEN, what other factor(s) does mass affect?
50
9.
Use the information below to plot the stars on the H-R Diagram given, and identify each star using the numbers for
each. Finally, DETERMINE THEIR SIZES USING THE DIAGONAL LINES.
Stars
Surface temp
1. Antares:
3,500 K
2. Pollux:
4,700 K
3. Capella:
4. Spica:
Luminosity
Stars
Surface temp
Luminosity
Size (radius)
6. Vega:
9,500 K
32x
7. Deneb:
9,000 K
260,000x
5,000 K
141x
8. Arcturus:
4,400 K
113x
25,000 K
2,200x
9. Betelgeuse:
3,500 K
9,700x
1.5x
10. Sirius B
5. Alpha Centaurus 5,800 K
11,000x
Size (radius)
25,000 K
50x
0.002x
FILL IN THE “SIZE”
BOXES AFTER YOU
PLOT.
Question: How is the size of a star related to luminosity (absolute brightness)?