Astronomy 10
Spring 2008
Midterm 3, In-class activity 22, 4/15-4/17 CPS
(Posted 080424)
Note: two versions, "x" and "xx"
1. (Q7.1)
a = aa = 3.0 points
2. (Q8.2)
e = dd = 3.0 points
3. (Q8.4)
b = aa = 3.0 points
4. (Q8.51)
a = cc = 3.0 points
5. (Q9.4)
b = ee = 3.0 points
6. (M3.1)
b = bb = 3.0 points
7. (M3.2)
e = cc = 3.0 points
8. (M3.3)
a = ee = 3.0 points
9. (M3.4)
d = aa = 3.0 points
10. (M3.5)
a = dd = 3.0 points
=====
(For the short-answer questions, refer to the grading comments below for
specific details as to what these letters mean.)
=====
11. (Q8.3)
p = 15/15: Correct. The Stefan-Boltzmann law states that luminosity depends on
both the size (surface area) of the star, and its temperature. Thus a merely
warm star can still be more luminous than a hotter star if the warm star is much
bigger in size than the hotter star.
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraenous/tangential information; or has minor errors.
Stefan-Boltzmann law is garbled, but at least understands how size can be
independent from temperature in determining the luminosity of a star.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. Discussion based somehow on Wien's law and/or the
Stefan-Boltzmann law.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner. Typically confuses luminosity
with apparent magnitude by saying that the warm star could be closer to the
Earth than the hotter star, when in fact luminosity (and _absolute_ magnitude)
are unaffected by distance.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
12. (Q9.5)
p = 15/15: Correct. The OBAFGKM main sequence runs from massive to medium to
low-mass. Massive stars become main sequence stars sooner, and spend less time
as main sequence stars than medium mass stars. Since cluster 1 (OBAFGK) has
more medium-mass stars on the main sequence than cluster 2 (OBAF), then cluster
1 must be older, as more time was required for its spectral class G and K stars
to reach its main sequence.
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraenous/tangential information; or has minor errors. Recognizes the
relationship between mass (inferred from spectral type -> temperature ->
luminosity -> mass along the main sequence line), and main sequence lifetime,
but rest of discussion is garbled or incomplete.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. At least mentions some understanding of the relationships between
mass and evolution times.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
13. (M3.4)
p = 15/15: Correct. The Sun is not mass enough for its core to continue past
becoming degenerate C, and thus its core will become a white dwarf, while its
outer layers will be shed as a planetary nebula. A more massive star would
develop an Fe core that would undergo neutronization collapse when fusion ends,
resulting in a type II supernova. The surviving core would then become a
neutron star, which might also become a pulsar. Adequately describes either
what the Sun would eventually become (white dwarf), or why the Sun cannot become
a neutron star (pulsar).
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraneous/tangential information; or has minor errors.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. At least demonstrates understanding that the Sun is not massive
enough to become a supergiant -> type II supernova -> neutron star, and/or
understands the properties of a pulsar that presumably cannot be attained by the
medium-mass Sun.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner. Explains that the Sun will
become a pulsar, or explains that the Sun cannot become a pulsar because it is
too massive.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit. Statement unspported by evidence/explanation.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
Midterm 3 average = 47.8/75
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 MT3 A22 CPS
0000 d a b e c d a a d b p v y 31.5 3.0
0223 a e b e b b e a d a p p p 72 3.0 9.3
0501 aa aa bb aa aa bb cc ee aa cc p p p 60 3.0 9.3
1022 a d b e d b e d d a p v t 48 3.0
1191 d d a a d d e a b d v y x 19.5 3.0 9.3
1223 a e b a b c e a d a p p p 72 3.0 9.0
1231 a e a c b b e d a d p v v 42 3.0 9.3
1268 a d b e b c a c e d t v v 30 3.0 9.3
1307 aa cc aa aa ee aa cc aa aa dd t v x 36
1313 aa dd aa dd ee bb ee ee aa dd p r t 60 3.0 9.3
1361 a e c e d a d a d b v x x 24
1379 a e a a a b e a d e p t p 60 3.0 9.3
1388 a e b e b b e a d e r r t 57 3.0 9.3
1408 dd aa aa bb dd ee cc ee bb bb t v x 27 3.0 9.3
1721 aa cc bb ee aa bb cc ee bb ee p r t 48 3.0 9.3
1839 a c a a e a c a a d t v p 39
1882 aa dd bb ee dd aa ee ee aa dd r t v 42 3.0 9.3
1910 aa cc aa cc cc cc cc aa bb ee t t x 33
1917 aa dd aa ee cc aa bb ee bb bb r t z 33 0 0
1967 a c b a a b e a b a p r t 57 3.0 9.3
2232 dd bb aa bb ee bb ee ee aa cc r v x 36 3.0 9.3
2424 dd cc dd cc cc aa bb aa aa cc v r x 27 3.0 9.3
2849 0
2887 aa cc aa ee ee dd cc ee aa aa r p p 60 3.0 9.3
3773 aa cc aa dd ee bb cc ee aa dd p v v 51 3.0 6.9
3951 aa cc aa cc cc bb cc ee aa bb t v v 42 3.0 9.0
4257 a b a a e c b d d b r v v 33 3.0 9.3
4607 aa dd aa cc ee bb z z z dd p p p 66 3.0 9.3
4747 aa dd aa ee dd bb cc bb aa dd r r v 51 3.0 9.3
4888 a b a d a b d a e d v v v 27 3.0 9.3
5006 c e b a c b e a d e t r t 51
5282 aa dd aa cc ee cc cc ee aa dd p t t 60 3.0 9.3
5352 aa dd ee ee aa cc cc ee aa aa p t r 51 3.0 9.3
5456 a e b e b c e a d e p t r 57 0 2.4
5511 2.4
6221 a e b e b a e a d a p t t 57 3.0 9.3
6421 a e b b e a e a d a p r p 63 3.0 9.3
6562 aa cc bb ee bb aa cc ee aa cc p r t 48 3.0 9.3
7045 aa dd aa ee ee bb cc ee aa dd r t t 57 3.0 8.7
7704 aa dd bb dd ee bb bb ee aa dd r v v 45 0 2.4
7863 3.0 6.9
8703 aa ee aa bb bb bb cc bb aa dd p t r 54 3.0 8.4
8980 c e b e b b e a d e r v p 54 3.0 9.3
NOTES:
*Do not forget your Ast 10 PIN number!
*The cumulative class CPS review score was 92%, which means double
participation bonus for the review.
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