NSCI 111 ASTRONOMY TEST #4 6/30/2007 Dr.
Holmes NAME
ANSWER ALL THE QUESTIONS. THE WORTH OF EACH
QUESTION IS IN () AFTER THE QUESTION.
1. (10) Fill in the following for two stars
(excluding the sun)
|
Name of star |
Constellation in which star is found |
Absolute Magnitude |
Apparent Magnitude |
Distance from Earth |
Spectral Class |
|
. |
. |
. |
. |
. |
. |
|
. |
. |
. |
. |
. |
. |
2. (16) Draw an H-R diagram, labeling both
axes and indicating where the main sequence, giants, supergiants and white
dwarfs are located. Also, place the sun and the two stars of problem #1 on the
diagram.
3. (a) (4) What is a sunspot?
(b) (4) What is the solar wind?
4. (6) Name and briefly describe two ways
distances to the stars are determined.
1.
2.
5. (6) Name and briefly describe two of the
ways of detecting binary stars:
1.
2.
6. (5) Why are binary stars important (i.e.,
how do they help us determine stellar properties) ?
7. a) (3) Distinguish between brightness and
luminosity:
b) (3) Distinguish between apparent
magnitude and absolute magnitude:
8. (9)
Name three possible ways a star will end up after it has finished
burning its fuel:
1.
2.
3.
9. (4) What property of a star determines
which of the above ways that star will end up?
10. a) (3) What is a Cephied variable star?
b) (3) Why is this type of star important?
11. (10) Draw another H-R diagram, labeling
the axes and showing the position of the main sequence, and then draw in the
life cycle of a star like the sun, and explain what is happening at each
stage of the cycle.
12. a) (2) What is a neutron star?
b) (2)
When is a neutron star formed?
13. TRUE or FALSE: (+1 points each if
correct, 0 if left blank, -1 if wrong)
(or
subtracting from 100: -0 if correct, -1 if blank, -2 if wrong)
__T___ a) The
diameter of the sun is about 1% of the earth-sun distance (about means within a
range from 0.5% to 5%). Therefore it is
larger than the earth to moon distance.
__F___ b) The
sun should last a total of about 10 million years on the main sequence (about means
within a range from 1 million to 100 million).
__T___ c) The
average power from the sun falling on one square meter on the earth’s surface
is about 250 Watts (about means within a range from 100 to 1000).
__F___ d) Binary star systems
are relatively rare. Most stars that we see are single stars like the sun.
__F__ e) Some nebulae appear to be the result of
exploding planets while others appear to be the result of exploding stars.
__T___ f) While
the distance to the sun is several light minutes, the distance to the nearest
star (excluding the sun) is several light years.
__F__ g) Sunspots are permanent spots on the sun’s
surface. They have lasted as long as we
have been able to observe the sun.
Galileo saw the exact same spots we see today.
__F___ h) When
the sun's hydrogen in its core is used up, the outer parts of the sun will
probably expand to beyond the orbit of Pluto as the sun becomes a red giant
star.
__F___ i) A
supernova is when a star literally explodes and blows itself apart. The energy output during the explosion is
equivalent to that of around a hundred normal stars.
__F___ j) More
massive stars last longer on the main sequence than less massive stars because
they have more fuel (mass).