Download Astro 1 & 100 Levine Homework Stars Name:____________________________

Astro 1 & 100
Levine
Homework Stars
KEY
Name:____________________________
______/29
Part I — Properties of Stars
You may want to do the lecture-tutorial on pg 33, Apparent and Absolute Magnitude of
Stars, prior to doing this portion of the homework, if you need a refresher on m and M.
Ranking questions are 2 points each. Consider the following table of stars:
ID for
ranking
Name
Apparent
Absolute
Spectral Class m-M
magnitude (m) magnitude (M)
(complete
this)
SB
Sirius B
8.3
11.2 B4-B5
-2.9
Sph
Saiph
2.1
-6.1 B0-B1
8.2
AC
Alpha Centauri
A
Vga
Vega
Btl
G75
-0.01
4.4 G2
-4.4
0
0.6 A0
-0.6
Betegeuse
0.5
-7.2 M2
7.7
Gl 75
5.6
5.6 K0
0
1. Rank these stars in order of luminosity, from brightest to dimmest :
Btl
Sph
vga
AC
GL75 SB
Brightest ______ ______ ______ ______ ______ ______ Dimmest
Or, all have the same luminosity ______________
2. Rank these stars in order of apparent brightness, from brightest to dimmest:
AC
Vga
Btl
Sph
G75
SB
Brightest ______ ______ ______ ______ ______ ______ Dimmest
Or, all have the same apparent brightness ______________
3. Rank these stars in order of distance from the Sun, from closest to farthest (Hint:
you only need to know m — M to figure this out!)
AC
SB
Vega
G75
Btl
Sph
Closest ______ ______ ______ ______ ______ ______ Farthest
Or, all are at the same distance ______________
4. Rank these stars in order of color from reddest to bluest:
Btl
G75
AC
Vga
SB
Sph
Reddest ______ ______ ______ ______ ______ ______ Bluest
Or, all have the same color ______________
5. Rank these stars in order of temperature from hottest to coolest:
Sph
SB
Vga
AC
G75
Btl
Hottest ______ ______ ______ ______ ______ ______ Coolest
Or, all have the same temperature ______________
Page 1
! of !4
II
6
7
8
Astro 1 & 100
Levine
Homework Stars
9. Which of the stars from the Star Table are main sequence stars? (2 points)
Saiph, Vega, Alpha Centauri A and GL75
10. Which of the stars from the Star Table are red giants or red supergiants? (2 points)
Betelgeuse (red supergiant)
11. Which of the stars from the Star Table are white dwarfs? (2 points)
Sirius B
12. Which of the stars from the Star Table is most similar to the Sun? (2 points)
Alpha Centauri A.
Alpha Centauri A. It has almost identical spectral type and just a bit lower luminosity.
Note: the Sun, by definition, has a luminosity of 1.0 on this chart, which equates to M=5.
Page 3
! of !4
Astro 1 & 100
Levine
Homework Stars
Part III-- Stellar Evolution
13. Fill out the following diagram with the evolutionary stages given in the box. (5
points)
Protostar
3 M☉ MS Star
30 M☉ MS Star
Red Giant
Supergiant
Planetary Nebula
Type II Supernova
White Dwarf
Black Hole
Type Ia Supernova
Page 4
! of !4
Neutron Star