Download Stars and Galaxies: The H

Stars and Galaxies: The H-R Diagram
When the luminosity of stars if plotted against the temperature it is found that the stars
fall into groups on the graph. These groups represent stages of a star’s life cycle from the
formation from gas and dust in a nebula to the end of the energy output from the star.
During the time when a star is “burning” hydrogen it is in the Main Sequence of stars on
the graph. When a star runs out of hydrogen fuel sever events could happen depending
on the mass and temperature of the star. High mass stars become super giants ending in
supernova and either a black hole or a neutron star.
Label a diagram of a stellar life cycle:
Black
Hole
1-white dwarf, 2-red giant, 3-red supergiant, 4-high-mass star, 5-low-mass star, 6supernova, 7-neurton star
H-R Diagram: Negative magnitude is brighter than positive magnitude
Based on the H-R diagram
8. Which star is cooler than our sun?
A. Antares
B. Rigel
C. Vega
D. White Dwarfs
9. What is the approximate magnitude of Rigel?
A. -2.5
B. 2.5
C. 25000
D. O
10. Which are hotter than our sun?
A. all main sequence stars
C. all red giants
B. all white dwarfs
D. all supergiants
11. What type of star is Betelgeuse?
A. main sequence
C. white dwarf
B. super giant
D. red giant
12. The sun is brighter than___
A. red giants
C. white dwarfs
B. super giants
D. all main sequence stars
Try your own graph of the stars
Temp
Luminosity
(Kelvin)
Wolf 359
Sirius A
Epsilon
Eridani
Procyon A
Vega
Altair
Spica
2,700
10,400
4,500
(Sun = 1)
(Absolute)
0.00003
23
0.3
6,500
10,700
8,000
21,000
7.3
55
11
2800
* 28
* 29
* 30
* 31
* 32
Arcturus
Betelgeuse
Aldebaran
Antares
Delta Aquarii
B
4,500
3,200
4,200
3,400
6,000
110
17000
100
5000
4300
* 33
* 34
Sirius B
Procyon B
10,700
7,400
0.0024
0.00055
*5
*7
* 12
* 16
* 18
* 21
* 22