Download Astronomy Assignment #1

Astronomy Assignment #7
Your Name______________________________________
Your Class Meeting Time __________________________
This assignment is due on __________________________
Submit this cover sheet with your assignment.
Complete the assigned problems from the text listed below and address the Instructor Assigned Topic.
Mathematical problems may be hand written. Write out the problem, show your work in solving the problem
and state your answer in a complete sentence. Failure to complete all three of these tasks will result in less
than full credit awarded. The Instructor assigned topic must be typed.
Text Problems:
Unit Number
36
Questions for Review
6, 7, 9, 10
Problems
Instructor Assigned Topic:
1.
Summarize the material in Unit 35.2 through 35.5 by replacing each paragraph in each section with a single sentence. For
example, section 35.2 is composed of seven paragraphs. Thus this section should be summarized in seven sentences. The
first paragraph in section 35.2 could be summarized as follows:
35.2 Birth of the Solar System
“ The Solar Nebula Theory, first proposed by Immanuel Kant and Pierre Simon Laplace in the 18’th century that
describes the origin of the solar system as originating from a disk shaped cloud of gas and dust, explains the
flattened shape of our solar system and the common direction of motion of the planets around the Sun.”
Continue to compress each paragraph into a single sentence until the section is completed, then compress the next section in
like manner. Also include one sentence summaries of the important figures: Fig 35.3, 35.6, 35.7, 35.8 and 35.10 in their
respective sections.
2.
Complete the attached Sample Calculation using the Doppler Detection Method for the star GJ 3021following the example
we did in class. Do not complete this second Instructor Assigned Topic
Sample Calculation using the Doppler Detection Method
Star
:
GJ 3021
Spectral Type G6 V
Mass 0.9 Solar Masses
Radial Velocity Curve
-5.61 km/s
-5.94 km/s
51,125 d
51,528 d
Measured Quantities
Period of the star’s “wobble”:_________________________________
Amplitude, K, of the star’s velocity “wobble”: ____________________
Derived Quantities
Period of the planet causing the “wobble”:__________________
Semi-major axis of the planet’s orbit from Kepler’s 3rd law:
r3 


G
 P 2  M Star 
2
4
Semi-major axis of the planet’s orbit = ______________
Orbital Velocity of the planet:
2
vOrbit 
GM Star

r
Using momentum conservation, estimate the minimum mass of the planet:
M Star  K  mPlanet  vOrbital
mPlanet 
M Star  K

vOrbital
Estimated minimum mass of the planet is ____________
Since the radial velocity curve appears to very much like a sine wave, the orbit must be nearly circular
with almost zero eccentricity.
Summary Table
Planet: ______________
Period of Planet’s Orbit
Radius of Planet’s Orbit
Minimum Mass of Planet
Eccentricity
Seconds
meters
kg
Circular or Non-circular
Years
AU
Jupiter Masses
---------------------------
In a paragraph, compare the planetary system around GJ 3012 to our own solar system. You may
assume that there are other planets around GJ 3021 that have not been detected yet. Is this planetary
system like our own? Be quantitative in your comparison.
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