Astronomy 210 Quiz 7, spring semester 2016
Cuesta College, San Luis Obispo, CA
According to the monolithic collapse model, the oldest stars in the Milky Way are located:
(A) in the halo.
(B) in the nuclear bulge.
(C) within the spiral arms.
(D) inside the central supermassive black hole.
Correct answer (highlight to unhide): (A)
According to the monolithic collapse model, the Milky Way evolved from a spherical shape to its current disk shape, leaving behind the globular clusters out in its halo. Thus globular clusters should all have the identical (old) ages (as determined from the lack of metal absorption lines, and their H-R diagram turn-off points), while the nuclear bulge and the spiral arms should be comprised of mixed-age (old and newer) stars.
Section 30674
Exam code: quiz07N4rK
(A) : 10 students
(B) : 1 student
(C) : 6 students
(D) : 0 students
"Success level": 61% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.47
Showing posts with label interstellar matter. Show all posts
Showing posts with label interstellar matter. Show all posts
20160421
Astronomy quiz question: Lagoon Nebula colors
Astronomy 210 Quiz 6, spring semester 2016
Cuesta College, San Luis Obispo, CA
ESO/VPHAS+ team
eso.org/public/usa/images/eso1403a/
[Version 1] The Lagoon Nebula (Messier 8/NGC 6523) is observed to have regions of pink and dark brown colors. The composition of its pink color regions is:
(A) helium gas.
(B) hydrogen gas.
(C) very small dust particles.
(D) dense clumps of large dust particles.
Correct answer (highlight to unhide): (B)
The pink colors are the combination of red, violet, and blue photons given off by excited hydrogen electrons jumping down to lower orbitals.
Section 30674
Exam code: quiz06ncM7
(A) : 4 students
(B) : 9 students
(C) : 7 students
(D) : 0 students
Success level: 48% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20
[Version 2] The Lagoon Nebula (Messier 8/NGC 6523) is observed to have regions of pink and dark brown colors. The composition of its dark brown color regions is:
(A) helium gas.
(B) hydrogen gas.
(C) very small dust particles.
(D) dense clumps of large dust particles.
Correct answer (highlight to unhide): (D)
The dark brown color is due to large, clumpy dust particles blocking visible light.
Section 30676
Exam code: quiz06sRR0
(A) : 1 student
(B) : 5 students
(C) : 7 students
(D) : 35 students
Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.29
Cuesta College, San Luis Obispo, CA
ESO/VPHAS+ team
eso.org/public/usa/images/eso1403a/
[Version 1] The Lagoon Nebula (Messier 8/NGC 6523) is observed to have regions of pink and dark brown colors. The composition of its pink color regions is:
(A) helium gas.
(B) hydrogen gas.
(C) very small dust particles.
(D) dense clumps of large dust particles.
Correct answer (highlight to unhide): (B)
The pink colors are the combination of red, violet, and blue photons given off by excited hydrogen electrons jumping down to lower orbitals.
Section 30674
Exam code: quiz06ncM7
(A) : 4 students
(B) : 9 students
(C) : 7 students
(D) : 0 students
Success level: 48% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20
[Version 2] The Lagoon Nebula (Messier 8/NGC 6523) is observed to have regions of pink and dark brown colors. The composition of its dark brown color regions is:
(A) helium gas.
(B) hydrogen gas.
(C) very small dust particles.
(D) dense clumps of large dust particles.
Correct answer (highlight to unhide): (D)
The dark brown color is due to large, clumpy dust particles blocking visible light.
Section 30676
Exam code: quiz06sRR0
(A) : 1 student
(B) : 5 students
(C) : 7 students
(D) : 35 students
Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.29
20151215
Astronomy quiz question: interstellar gas and dust in the Milky Way
Astronomy 210 Quiz 7, fall semester 2015
Cuesta College, San Luis Obispo, CA
Interstellar gas and dust in the Milky Way prevents most of its __________ from being visible from Earth.
(A) stars.
(B) dark matter.
(C) radio waves.
(D) neighboring galaxies.
Correct answer (highlight to unhide): (A)
Interstellar gas and dust blocks visible light from stars, while typically not affecting longer wavelength forms of light such as radio waves. Dark matter is not visible already, and clear views of our neighboring galaxies can be seen above and below the gas and dust in the disk of the Milky Way.
Section 70158
Exam code: quiz07srrH
(A) : 32 students
(B) : 1 student
(C) : 0 students
(D) : 6 students
Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.62
Section 70160
Exam code: quiz07nM0r
(A) : 18 students
(B) : 1 student
(C) : 1 student
(D) : 6 students
Success level: 75% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64
Cuesta College, San Luis Obispo, CA
Interstellar gas and dust in the Milky Way prevents most of its __________ from being visible from Earth.
(A) stars.
(B) dark matter.
(C) radio waves.
(D) neighboring galaxies.
Correct answer (highlight to unhide): (A)
Interstellar gas and dust blocks visible light from stars, while typically not affecting longer wavelength forms of light such as radio waves. Dark matter is not visible already, and clear views of our neighboring galaxies can be seen above and below the gas and dust in the disk of the Milky Way.
Section 70158
Exam code: quiz07srrH
(A) : 32 students
(B) : 1 student
(C) : 0 students
(D) : 6 students
Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.62
Section 70160
Exam code: quiz07nM0r
(A) : 18 students
(B) : 1 student
(C) : 1 student
(D) : 6 students
Success level: 75% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64
20150425
Astronomy quiz question: light passing through a dark nebula
Astronomy 210 Quiz 6, spring semester 2015
Cuesta College, San Luis Obispo, CA
__________ light can be seen from stars behind a dark nebula.
(A) Blue.
(B) Infrared.
(C) Ultraviolet.
(D) Doppler shifted.
Correct answer (highlight to unhide): (B)
Dust particles will scatter shorter wavelength light more than longer wavelengths. Infrared light, which is the longest wavelength light listed here, should be least affected by passing through a dark nebula.
Section 30676
Exam code: quiz06n1iI
(A) : 10 students
(B) : 20 students
(C) : 6 students
(D) : 30students
"Success level": 59% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.48
Cuesta College, San Luis Obispo, CA
__________ light can be seen from stars behind a dark nebula.
(A) Blue.
(B) Infrared.
(C) Ultraviolet.
(D) Doppler shifted.
Correct answer (highlight to unhide): (B)
Dust particles will scatter shorter wavelength light more than longer wavelengths. Infrared light, which is the longest wavelength light listed here, should be least affected by passing through a dark nebula.
Section 30676
Exam code: quiz06n1iI
(A) : 10 students
(B) : 20 students
(C) : 6 students
(D) : 30students
"Success level": 59% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.48
Astronomy quiz question: blue color of a reflection nebula
Astronomy 210 Quiz 6, spring semester 2015
Cuesta College, San Luis Obispo, CA
A reflection nebula appears to be blue because its dust particles:
(A) absorb red light.
(B) scatter blue light.
(C) emit blue photons.
(D) have cool temperatures.
Correct answer (highlight to unhide): (B)
Very small dust particles will scatter short-wavelength (blue) light in all directions more than scattering longer wavelengths of visible light (all other colors), such that this nebula will appear blue in color.
Section 30676
Exam code: quiz06szLR
(A) : 3 students
(B) : 37 students
(C) : 7 students
(D) : 0 students
Success level: 81% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.46
Cuesta College, San Luis Obispo, CA
A reflection nebula appears to be blue because its dust particles:
(A) absorb red light.
(B) scatter blue light.
(C) emit blue photons.
(D) have cool temperatures.
Correct answer (highlight to unhide): (B)
Very small dust particles will scatter short-wavelength (blue) light in all directions more than scattering longer wavelengths of visible light (all other colors), such that this nebula will appear blue in color.
Section 30676
Exam code: quiz06szLR
(A) : 3 students
(B) : 37 students
(C) : 7 students
(D) : 0 students
Success level: 81% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.46
20121123
Astronomy quiz question: mapping Milky Way spiral arms
Astronomy 210 Quiz 6, fall semester 2012
Cuesta College, San Luis Obispo, CA
__________ is/are evidence that spiral arms extend across the entire Milky Way disk.
(A) Positions of massive main sequence stars.
(B) Radio waves emitted from cold hydrogen gas clouds.
(C) Globular cluster positions.
(D) The Doppler effect.
Correct answer: (B)
Radio waves are relatively unaffected by interstellar gas and dust, and enable the locations of cold hydrogen gas clouds in most of the Milky Way to be mapped. Positions of massive main sequence stars can only give an indication of spiral arms immediately adjacent to the spur the sun is located in; and globular cluster positions are used to determine the location of the Milky Way.
Section 70158
Exam code: quiz06Sl4m
(A) : 9 students
(B) : 4 students
(C) : 13 students
(D) : 4 students
Success level: 19% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.38
Cuesta College, San Luis Obispo, CA
__________ is/are evidence that spiral arms extend across the entire Milky Way disk.
(A) Positions of massive main sequence stars.
(B) Radio waves emitted from cold hydrogen gas clouds.
(C) Globular cluster positions.
(D) The Doppler effect.
Correct answer: (B)
Radio waves are relatively unaffected by interstellar gas and dust, and enable the locations of cold hydrogen gas clouds in most of the Milky Way to be mapped. Positions of massive main sequence stars can only give an indication of spiral arms immediately adjacent to the spur the sun is located in; and globular cluster positions are used to determine the location of the Milky Way.
Section 70158
Exam code: quiz06Sl4m
(A) : 9 students
(B) : 4 students
(C) : 13 students
(D) : 4 students
Success level: 19% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.38
Astronomy quiz question: Milky Way halo new star formation?
Astronomy 210 Quiz 6, fall semester 2012
Cuesta College, San Luis Obispo, CA
There is no new star formation in the halo of the Milky Way because there is/are no __________ left in the halo.
(A) luminous matter.
(B) metals.
(C) interstellar hydrogen.
(D) type II supernova shockwaves.
Correct answer: (C)
New stars form from hydrogen clouds, which are present in the disk of the Milky Way, but not in the halo.
Section 70158
Exam code: quiz06Sl4m
(A) : 3 students
(B) : 4 students
(C) : 20 students
(D) : 3 students
Success level: 66% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64
Section 70160
Exam code: quiz06n4Rd
(A) : 2 students
(B) : 3 students
(C) : 18 students
(D) : 2 students
Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
Cuesta College, San Luis Obispo, CA
There is no new star formation in the halo of the Milky Way because there is/are no __________ left in the halo.
(A) luminous matter.
(B) metals.
(C) interstellar hydrogen.
(D) type II supernova shockwaves.
Correct answer: (C)
New stars form from hydrogen clouds, which are present in the disk of the Milky Way, but not in the halo.
Section 70158
Exam code: quiz06Sl4m
(A) : 3 students
(B) : 4 students
(C) : 20 students
(D) : 3 students
Success level: 66% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64
Section 70160
Exam code: quiz06n4Rd
(A) : 2 students
(B) : 3 students
(C) : 18 students
(D) : 2 students
Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
20120718
Presentation: interstellar medium
In previous presentations we've discussed the sizes of stars, and their source of energy, but consider the space between stars--it is not empty, but contains clouds of hydrogen gas and dust... (Video link: "Stars and Nebulae.")
In this presentation we will discuss the different types of clouds in the interstellar medium, and how stars form these clouds.
First, distinguishing between three different types of clouds, or nebulae.
An emission nebula is a cloud of hydrogen atoms, illuminated by a nearby star. We have an observer in space, with a spacesuit on (because that was important to some students). Photons with sufficient energy from the star will be absorbed by the hydrogen atom's electron, freeing it. As the electron falls back down to lower orbitals, it may give off a violet photon, or a blue photon, or a red photon (in the visible light range, among a multitude of other possible photons). These violet, blue, and red photons are perceived by the observer's naked eye as a pinkish lavender color.
Conversely, if you see a pink cloud in space, then you know that it is composed of predominately hydrogen.
A reflection nebula is a diffuse cloud of tiny dust particles, similar in size to cigarette smoke particles. Again a nearby star illuminates this cloud, but short-wavelength blue light and long-wavelength red light behaves differently. Red light kind of just "wiggles" through the dust cloud, but blue light gets scattered in all directions. To the observer's naked eye, the cloud will appear blue--much like cigarette smoke does. 
Again, conversely, if you see a blue cloud in space, it must be composed of diffuse, tiny dust particles.
A dark nebula is a thick cloud of large, clumpy dust particles, thick enough that light from a nearby star...is completely blocked by the cloud.
So if you see a dark splotch in space, it is composed of thick, clumpy dust particles. (Or would it instead be a "rip" in space? What type of light would you look for to convince you that there are stars being blocked behind it, instead of "nothingness" behind it? Extremely short wavelengths, or long wavelengths?)
Let's start our picto-quiz--what type of nebula is this? What is it made of? 
What type of nebula is this? What is it made of?
What types of nebulae is this? What two types of material is it made of? By the way, this is also known as the "Horsehead Nebula"--like a chess piece horse, instead of a My Little PonyTM horse. Or does it look more like a Dementor from J. K. Rowling's Harry Potter book series? 
What types of nebulae is this? What parts of this is composed of what? Do you see "Thor's Helmet?"
What type of nebula is this? What is it made of? When you look at this nebula, what does it look like to you?
Second, star formation in the interstellar medium.
Note only pink, blue, and brown/black colors in this cloud. Any other colors that you see in real and simulated views of outer space are "fake" in that they are either enhanced false colors, or mere artistic impressions. Think about that when you pick up a science magazine, or what a documentary or science-fiction movie on television. A molecular cloud is cool enough that atoms and molecules are moving slowly such that if they collide, then will bind to each other rather than bounce of each other. If you wait long enough, these molecules will form larger and larger clumps, such that their gravity will get stronger and start pulling in even more material, to build stars (and perhaps planets), given enough time. This process is "self-starting" as given enough time, a cloud will eventually settle down and start building stars, although this will be excruciatingly slow. (Video link: "Star-Forming Region.")
20120422
Astronomy quiz question: interstellar hydrogen hyperfine lines
Astronomy 210 Quiz 6, spring semester 2012
Cuesta College, San Luis Obispo, CA
Radio waves emitted from cold hydrogen gas clouds provides evidence of:
(A) spiral arms extending across the entire Milky Way disk.
(B) the central supermassive black hole.
(C) dark matter.
(D) unequal amounts of matter and antimatter.
Correct answer: (A)
Radio waves are relatively unaffected by interstellar gas and dust, and enable the locations of cold hydrogen gas clouds in most of the Milky Way to be mapped.
Section 30674
Exam code: quiz06niLl
(A) : 16 students
(B) : 5 students
(C) : 5 students
(D) : 4 students
"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.44
Cuesta College, San Luis Obispo, CA
Radio waves emitted from cold hydrogen gas clouds provides evidence of:
(A) spiral arms extending across the entire Milky Way disk.
(B) the central supermassive black hole.
(C) dark matter.
(D) unequal amounts of matter and antimatter.
Correct answer: (A)
Radio waves are relatively unaffected by interstellar gas and dust, and enable the locations of cold hydrogen gas clouds in most of the Milky Way to be mapped.
Section 30674
Exam code: quiz06niLl
(A) : 16 students
(B) : 5 students
(C) : 5 students
(D) : 4 students
"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.44
20120420
Astronomy quiz question: only portion of Milky Way visible
Astronomy 210 Quiz 6, spring semester 2012
Cuesta College, San Luis Obispo, CA
Only a small portion of the Milky Way disk is visible to the naked eye because of:
(A) the finite speed of light.
(B) dark matter.
(C) interstellar gas and dust.
(D) expanding space.
Correct answer: (C)
Section 30674
Exam code: quiz06niLl
(A) : 1 student
(B) : 3 students
(C) : 28 students
(D) : 1 student
"Success level": 86% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.33
Section 30676
Exam code: quiz06suE7
(A) : 1 student
(B) : 5 students
(C) : 26 students
(D) : 3 students
"Success level": 76% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.56
Cuesta College, San Luis Obispo, CA
Only a small portion of the Milky Way disk is visible to the naked eye because of:
(A) the finite speed of light.
(B) dark matter.
(C) interstellar gas and dust.
(D) expanding space.
Correct answer: (C)
Section 30674
Exam code: quiz06niLl
(A) : 1 student
(B) : 3 students
(C) : 28 students
(D) : 1 student
"Success level": 86% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.33
Section 30676
Exam code: quiz06suE7
(A) : 1 student
(B) : 5 students
(C) : 26 students
(D) : 3 students
"Success level": 76% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.56
20111117
Astronomy quiz question: monolithic collapse model
Astronomy 210 Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA
According to the monolithic collapse model, there should be no young stars in globular clusters because:
(A) metal-rich stars in the halo have already become metal-poor stars.
(B) there are no metals left in the halo.
(C) dark matter in the halo prevents new stars from forming.
(D) interstellar hydrogen in the halo moved into the disk.
Correct answer: (D).
Since the distribution of interstellar hydrogen in the Milky Way has flattened from spherical to disk-shaped, new star formation occurs only in the disk, and not in the halo, where the first generation stars of the globular clusters are located.
Section 70160
Exam code: quiz06n4Nd
(A) : 11 students
(B) : 4 students
(C) : 2 students
(D) : 9 students
Success level: 40% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.63
Cuesta College, San Luis Obispo, CA
According to the monolithic collapse model, there should be no young stars in globular clusters because:
(A) metal-rich stars in the halo have already become metal-poor stars.
(B) there are no metals left in the halo.
(C) dark matter in the halo prevents new stars from forming.
(D) interstellar hydrogen in the halo moved into the disk.
Correct answer: (D).
Since the distribution of interstellar hydrogen in the Milky Way has flattened from spherical to disk-shaped, new star formation occurs only in the disk, and not in the halo, where the first generation stars of the globular clusters are located.
Section 70160
Exam code: quiz06n4Nd
(A) : 11 students
(B) : 4 students
(C) : 2 students
(D) : 9 students
Success level: 40% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.63
20110502
Astronomy midterm question: other galaxies but our own visible?
Astronomy 210 Midterm 2, Spring Semester 2011
Cuesta College, San Luis Obispo, CA
[20 points.] Even though only a small fraction of the stars in own galaxy is visible from Earth, explain why we can still see stars of other galaxies outside the Milky Way with the naked eye. Support your answer using a diagram, and properties of galaxies.
Solution and grading rubric:
Section 30674
Exam code: midterm02N3n4
p: 14 students
r: 9 students
t: 6 students
v: 9 students
x: 0 students
y: 2 students
z: 0 students
A sample "p" response (from student 1450):
Cuesta College, San Luis Obispo, CA
[20 points.] Even though only a small fraction of the stars in own galaxy is visible from Earth, explain why we can still see stars of other galaxies outside the Milky Way with the naked eye. Support your answer using a diagram, and properties of galaxies.
Solution and grading rubric:
- p = 20/20:
Correct. Views along the disk of the Milky Way would be obscured by interstellar gas/dust, but views up and down, perpendicular to the plane of the Milky Way disk would be much less obscured, as space between galaxies is relatively empty, making the stars of galaxies visible. - r = 16/20:
Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. At least understands how shape of Milky Way is important, but may discuss other contributing factors. - t = 12/20:
Contains right ideas, but discussion is unclear/incomplete or contains major errors. - v = 8/20:
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Discusses some other aspects of the Milky Way. - x = 4/20:
Implementation/application of ideas, but credit given for effort rather than merit. - y = 2/20:
Irrelevant discussion/effectively blank. - z = 0/20:
Blank.
Section 30674
Exam code: midterm02N3n4
p: 14 students
r: 9 students
t: 6 students
v: 9 students
x: 0 students
y: 2 students
z: 0 students
A sample "p" response (from student 1450):
20110422
Astronomy quiz question: Milky Way spiral arm evidence
Astronomy 210 Quiz 6, Spring Semester 2011
Cuesta College, San Luis Obispo, CA
__________ is/are evidence that spiral arms extend across the Milky Way disk.
(A) Globular cluster positions.
(B) Positions of massive main sequence stars.
(C) The Doppler effect.
(D) Radio waves from cold hydrogen gas clouds.
Correct answer: (D)
While the luminous stars in response (B) is used to map out an indication of spiral arms and spurs in our immediate vicinity of the Milky Way, response (D) refers to the radio waves from cold hydrogen gas clouds that are relatively unobstructed by the interstellar gas and dust, and this data allows essentially the entire spiral arm structure of the Milky Way to be mapped. Response (A) refers to how the location of the center of the Milky Way is determined.
Section 30674
Exam code: quiz06n4Ke
(A) : 19 students
(B) : 8 students
(C) : 3 students
(D) : 7 students
"Success level": 22% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.30
Cuesta College, San Luis Obispo, CA
__________ is/are evidence that spiral arms extend across the Milky Way disk.
(A) Globular cluster positions.
(B) Positions of massive main sequence stars.
(C) The Doppler effect.
(D) Radio waves from cold hydrogen gas clouds.
Correct answer: (D)
While the luminous stars in response (B) is used to map out an indication of spiral arms and spurs in our immediate vicinity of the Milky Way, response (D) refers to the radio waves from cold hydrogen gas clouds that are relatively unobstructed by the interstellar gas and dust, and this data allows essentially the entire spiral arm structure of the Milky Way to be mapped. Response (A) refers to how the location of the center of the Milky Way is determined.
Section 30674
Exam code: quiz06n4Ke
(A) : 19 students
(B) : 8 students
(C) : 3 students
(D) : 7 students
"Success level": 22% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.30
20110411
Astronomy quiz question: light passing through a dark nebula
Astronomy 210 Quiz 5, spring semester 2011
Cuesta College, San Luis Obispo, CA
__________ light can be seen from stars behind a dark nebula.
(A) Infrared.
(B) Ultraviolet.
(C) Blue.
(D) Doppler shifted.
Correct answer: (B)
Dust particles will scatter shorter wavelength light more than longer wavelengths. Infrared light, which is the longest wavelength light listed here, should be least affected by passing through a dark nebula.
Section 30676
Exam code: quiz05s0F7
(A) : 19 students
(B) : 8 students
(C) : 8 students
(D) : 3 students
(No response): 1 student
"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.68
Cuesta College, San Luis Obispo, CA
__________ light can be seen from stars behind a dark nebula.
(A) Infrared.
(B) Ultraviolet.
(C) Blue.
(D) Doppler shifted.
Correct answer: (B)
Dust particles will scatter shorter wavelength light more than longer wavelengths. Infrared light, which is the longest wavelength light listed here, should be least affected by passing through a dark nebula.
Section 30676
Exam code: quiz05s0F7
(A) : 19 students
(B) : 8 students
(C) : 8 students
(D) : 3 students
(No response): 1 student
"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.68
20101115
Astronomy quiz question: the sun's Milky Way location
Astronomy 210 Quiz 6, Fall Semester 2010
Cuesta College, San Luis Obispo, CA
__________ is evidence that the sun is located near the outer rim of the Milky Way disk.
(A) Most stars in other galaxies are found near their outer rims.
(B) Very few stars in the direction out towards the rim.
(C) How slowly the sun orbits the center of the Milky Way.
(D) Star cluster positions above and below the disk.
Correct answer: (D)
Globular star clusters can be easily seen above and below the disk of the Milky Way, unimpeded by interstellar gas and dust within the disk of the Milky Way, and their locations are centered on the gravitational center of the Milky Way.
Section 70160
(A) : 1 student
(B) : 6 students
(C) : 14 students
(D) : 16 students
"Success level": 48% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.62
Cuesta College, San Luis Obispo, CA
__________ is evidence that the sun is located near the outer rim of the Milky Way disk.
(A) Most stars in other galaxies are found near their outer rims.
(B) Very few stars in the direction out towards the rim.
(C) How slowly the sun orbits the center of the Milky Way.
(D) Star cluster positions above and below the disk.
Correct answer: (D)
Globular star clusters can be easily seen above and below the disk of the Milky Way, unimpeded by interstellar gas and dust within the disk of the Milky Way, and their locations are centered on the gravitational center of the Milky Way.
Section 70160
(A) : 1 student
(B) : 6 students
(C) : 14 students
(D) : 16 students
"Success level": 48% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.62
20101112
Astronomy quiz question: globular star clusters
Astronomy 210 Quiz 6, Fall Semester 2010
Cuesta College, San Luis Obispo, CA
The locations of globular star clusters provide evidence for:
(A) the location of the Milky Way's center.
(B) dark matter in the halo.
(C) self-sustaining star formation.
(D) the spiral arm structure of the Milky Way.
Correct answer: (A)
Globular star clusters can be easily seen above and below the disk of the Milky Way, unimpeded by interstellar gas and dust within the disk of the Milky Way, and their locations are centered on the gravitational center of the Milky Way.
Section 70158
(A) : 22 students
(B) : 5 students
(C) : 2 students
(D) : 16 students
"Success level": 54% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.73
Cuesta College, San Luis Obispo, CA
The locations of globular star clusters provide evidence for:
(A) the location of the Milky Way's center.
(B) dark matter in the halo.
(C) self-sustaining star formation.
(D) the spiral arm structure of the Milky Way.
Correct answer: (A)
Globular star clusters can be easily seen above and below the disk of the Milky Way, unimpeded by interstellar gas and dust within the disk of the Milky Way, and their locations are centered on the gravitational center of the Milky Way.
Section 70158
(A) : 22 students
(B) : 5 students
(C) : 2 students
(D) : 16 students
"Success level": 54% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.73
20101103
Astronomy quiz question: type II supernova energy source
Astronomy 210 Quiz 5, Fall Semester 2010
Cuesta College, San Luis Obispo, CA
What provides the energy for a type II supernova explosion?
(A) Shockwaves from either nearby supernova explosions or hot young stars.
(B) Hydrogen fusion.
(C) Gravitational contraction.
(D) Convection.
Correct answer: (C)
Response (A) is how star formation may be triggered in the interstellar medium; response (D) is a consequence of heat from from the core to the surface of a star. Response (D) can no longer provide energy for a star at the end of its supergiant phase, as it core is iron at this point, past which requires more energy to be put in than can be released by fusion. Thus with no energy source to balance gravity, the core undergoes runaway contraction, and the resulting energy from this gravitational collapse of the core is transferred to the outer layers of the supergiant in an "implosion-explosion" sequence--a type II supernova.
Section 70158
(A) : 6 students
(B) : 5 students
(C) : 33 students
(D) : 0 students
"Success level": 77% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.83
Cuesta College, San Luis Obispo, CA
What provides the energy for a type II supernova explosion?
(A) Shockwaves from either nearby supernova explosions or hot young stars.
(B) Hydrogen fusion.
(C) Gravitational contraction.
(D) Convection.
Correct answer: (C)
Response (A) is how star formation may be triggered in the interstellar medium; response (D) is a consequence of heat from from the core to the surface of a star. Response (D) can no longer provide energy for a star at the end of its supergiant phase, as it core is iron at this point, past which requires more energy to be put in than can be released by fusion. Thus with no energy source to balance gravity, the core undergoes runaway contraction, and the resulting energy from this gravitational collapse of the core is transferred to the outer layers of the supergiant in an "implosion-explosion" sequence--a type II supernova.
Section 70158
(A) : 6 students
(B) : 5 students
(C) : 33 students
(D) : 0 students
"Success level": 77% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.83
20091029
Online reading assignment question: blue nebula composition
Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA
Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.
(The following question was asked before a presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)
A blue nebula is composed of __________. (Graded for completion.)
(A) Hydrogen gas.
(B) Very small dust particles.
(C) Dense clumps of large dust particles.
(D) Helium gas.
(E) (I'm lost, and don't know how to answer this.)
Student responses (pre-instruction)
Sections 70160
(A) : 13 students
(B) : 9 students
(C) : 7 students
(D) : 3 students
(E) : 0 students
Correct answer: (B)
Very small dust particles will scatter short-wavelength (blue) light in all directions more than scattering longer wavelengths, such that this nebula will appear blue in color.
(The same question above was asked of students in a different section, following the presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)
Student responses (post-instruction)
Sections 70158
(A) : 9 students
(B) : 14 students
(C) : 8 students
(D) : 4 students
(E) : 3 students
Cuesta College, San Luis Obispo, CA
Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.
(The following question was asked before a presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)
A blue nebula is composed of __________. (Graded for completion.)
(A) Hydrogen gas.
(B) Very small dust particles.
(C) Dense clumps of large dust particles.
(D) Helium gas.
(E) (I'm lost, and don't know how to answer this.)
Student responses (pre-instruction)
Sections 70160
(A) : 13 students
(B) : 9 students
(C) : 7 students
(D) : 3 students
(E) : 0 students
Correct answer: (B)
Very small dust particles will scatter short-wavelength (blue) light in all directions more than scattering longer wavelengths, such that this nebula will appear blue in color.
(The same question above was asked of students in a different section, following the presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)
Student responses (post-instruction)
Sections 70158
(A) : 9 students
(B) : 14 students
(C) : 8 students
(D) : 4 students
(E) : 3 students
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