PES Skill Sheets.book - Capital High School

4. Example answer: Edwin was incredibly excited today. Albert
Einstein came to visit him, and he even thanked him for all of
his hard work. It’s almost unbelievable! The most celebrated
scientist of our lifetime came to visit him. Just to be associated
with Einstein is an honor, let alone be thanked by him. Edwin
works very hard, and he must be very proud of his new
discoveries that have changed the world of astronomy.
Skill Sheet 28.2: Light Intensity
1. Example problem: 4.8 W/m 2
2. 0.0478 W/m 2
3. 0.0119 W/m 2
4. If distance from a light source doubles, then light intensity
decreases by a factor of 4. Example: 4 × 0.0119 W/m 2
approximately equals 0.0478 W/m 2 (see questions 2 and 3).
5. Answers are:
Skill Sheet 28.2: Henrietta Leavitt
1. Leavitt discovered new variable stars by comparing
photographic plates. The photographs showed the same
regions in the sky, but at different times. This allowed Leavitt
to examine the photos and identify stars that had changed in
size over time.
2. Leavitt studied Cepheid stars and found an inverse relationship
between a star’s brightness cycle and its magnitude. A stronger
star took longer to cycle between brightness and dimness. As a
result, she developed the Period-Luminosity relation.
3. The asteroid is called 5383 Leavitt.
4. The observatory was founded in 1839 and currently conducts
research in astronomy and astrophysics.
5. Example Answers:
Ejnar Hertzsprung:
Danish astronomer born October 8, 1873
Found the distance to the Small Magellan Cloud located
outside of the Milky Way Galaxy in 1913.
Skill Sheet 28.2: Calculating Luminosity
1. luminosity = 30 watts
power rating on bulb = 300 watts
2. luminosity = 1 watt
power rating on bulb = 10 watts
Skill Sheet 28.3: Doppler Shift
Part 1 answers:
1. Graphic, right
2a. B and D
2b. A and C
2c. C
2d. B
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5. The fact that the universe is expanding implies that it must
have been smaller in the past than it is today. The expanding
universe implies that the universe must have had a beginning.
This idea led to the development of the Big Bang theory,
which says that the universe exploded outward from a single
point smaller than an atom into the vast expanse of today’s
universe.
a. 0.005 W/m 2
b. 0.05 W/m 2
c. 0.5 W/m 2
d. 5 W/m 2
6. The watts of a light source and light intensity are directly
related. This means that if you use a light source that has 10
times the wattage, then light intensity will increase 10 times.
Developed the Hertzsprung-Russell diagram which
graphs the magnitude of stars against their surface
temperature or color.
Harlow Shapley:
Astronomer born November 2, 1885 in Nashville,
Missouri
In addition to being an astronomer, Shapley was a writer.
Shapley determined the size of the Milky Way Galaxy.
Edwin Hubble:
Astronomer born November 29, 1889 in Marshfield,
Missouri.
Earned an undergraduate degree in math and astronomy,
and went on to study law.
Developed a classification system for galaxies and created
Hubble’s Law which helped astronomers determine the
age of the universe.
3. Challenge:
luminosity = 1.370 × 10 3 (4π)(1.5 × 10 11 ) 2
= 1.370 × 10 3 (4π)(2.25 × 10 22 )
= 39 × 10 25
= 3.9 × 10 26 watts
Part 2 answers:
1. The star is moving away from Earth at a speed of
5.6 × 10 6 m/s.
2. The star is moving toward Earth at a speed of
8.6 × 10 6 m/s.
3. Galaxy B is moving fastest because it has shifted farther
toward the red (15 nm) than Galaxy A (9 nm).
4. It supports the Big Bang. This theory states that the universe
began from a single point and has been expanding ever since.