Sketchbook: stellar evolution

See if you can identify everything in this doodle.

Online reading assignment: Milky Way history, big bang clues (SLO campus)

Astronomy 210, fall semester 2019
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, a TED-talk video explanation of measuring extreme distances, and Minute Physics video explanations of Olbers' paradox and the expanding universe.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"What I found quite interesting is how many compounds/things today come from stars in the past. I've never thought about that."

"That the calcium in our bones, carbon in our body and iron in our blood were all formed from a past star...like, what???"

"That for stars such as Deneb when we do see them we're looking at their past form, not its current state."

"The concept of light-years and seeing stars, planets, and galaxies as they were so many years ago is really crazy to think about and super-cool. So basically, hypothetically, if the sun were to go out, we would have a nice 8-ish minutes before freezing to death."

"The concept of space and time is fascinating. One fact from the 'light seconds, light years, light centuries' video that I thought was cool: the Big Dipper appears to us the way it looked 80 years ago, because it took that long for light to travel to Earth."

"That we can use type Ia supernovae to tell how far away something is from us in space. I didn't realize that supernovae were brighter than their galaxies."

"The universe having finite age, but not a finite size."

"To think that there isn't an edge to our universe, and I could see why a lot of people go along with the misconception that there is a 'center to the universe.' There is no center, and it appears to be that the space between galaxies continue to expand over time. We're on the grow!"

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"I'm kind of confused on how the amounts of elements changed over time, but other than that I'm good."

"I'm confused by what each thing produces which element and things of that sort; it's just a lot to take in and it's confusing me."

"I'm confused about the production of elements. I think I might need to learn about it in person to truly grasp the concept."

"The monolithic collapse and bottom-up models are slightly confusing because they are both theories about the formation of the Milky Way. I have a feeling I may or may not mix them up."

"Why the universe keeps expanding and why do younger stars have more metal than older stars? Will the universe stop expanding? Since older stars fuse elements heavier than helium, shouldn't they have more metal?"

"How does the universe continually expand? How is there no limit or will there ever be a limit?"

"How the universe is infinite. It's crazy trying to wrap my head around that. How can it have no end? It just never ends? It's mind-blowing, really."

"The age and 'boundary' of the universe, and how it is determined. I think the human brain isn't evolved enough to grasp such complex (and almost metaphysical) topics, so things can start seeming very counter-intuitive. I am looking forward to our in-class discussion to clarify the topic."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [65%]
Metals (elements heavier than hydrogen and helium): increased [70%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	**** [4]
young stars that formed very recently.	**************** [16]
(There is a tie.)	[0]
(Neither, as stars cannot have metals.)	[0]
(Unsure/guessing/lost/help!)	[0]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [45%]
Helium in the sun's core: the sun [40%]
Carbon in your body: another star, in the past [65%]
Calcium in your bones: another star, in the past [50%]
Iron in your blood: another star, in the past [75%]
Gold and silver from mines: another star, in the past [45%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"At first there is nothing...bada bing bada boom...now the universe exists!"

"Thank you for giving us a constant supply of astronomy comics."

"This class has put me in an existential crisis."

"How is it even possible that the big bang occurred?" (I don't think we can ever answer 'why the big bang occurred,' but we are certainly able to answer 'how do we know the big bang occurred?')

"Will the final cover the last few chapters we are going over?" (Yes, along with the last quiz.)

"Do we have more than one Hubble telescope in space right now?" (The Hubble Space Telescope is designed to observe visible light; all the other space telescopes are designed to observe in different wavelengths (such as x-ray, infrared, etc.) that would be blocked by Earth's atmosphere.)

"Headline: 'Swiss Deny Dairy Product Influence on Moon Composition.'"

"How close are we to seeing the big bang?" (We see its after-effects everywhere around us.)

"If humans are made from stardust, then are there aliens also made from stardust?" (Yes, unless those aliens are made up only of hydrogen.)

Online reading assignment: Milky Way history, big bang clues (NC campus)

Astronomy 210, fall semester 2019
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, a TED-talk video explanation of measuring extreme distances, and Minute Physics video explanations of Olbers' paradox and the expanding universe.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"The big bang."

"The 'top-down' hypothesis of how the Milky Way galaxy was formed, and the big bang theory since both explain theories of how things came to be."

"I like how when we look at the stars we could be looking at a star that's possibly already dead."

"Watching the video about how astronomers measure the distance in light stars to a star was very interesting, it was a question I had on my mind when we briefly started talking about lightyears in class. I am still genuinely curious how it the math goes down step by step."

"That we are basically made up of stuff from stars that went supernova; so we are made up of dead stars that gave us the materials to make other stars and planets and eventually would lead to life using metals like iron, calcium, carbon, oxygen, and nitrogen that help to form the basic building blocks of life that would eventually lead to us."

"Learning about galaxies was pretty interesting, but it takes on a whole new layer of intrigue when we're talking about our own galaxy. Very cool."

"I found it interesting that the universe isn't finite but that it is infinite and that the universe may have a starting date meaning that there was a certain time that it didn't exist until it did."

"That for stars such as Deneb when we DO see them we're looking at its past form, not its current state."

"One thing I found interesting was the finite speed of light. It turns out that we have a time-machine of sorts to actually see the universe as it was in the past."

"It's comforting knowing that the galaxy is pretty much responsible for polluting itself. Humans haven't totally ruined everything. And the Milky Way is essentially a disgusting extra smog day in Los Angeles. Eeek! I also appreciated learning how light years are calculated and found it completely mind-blowing that I have looked at what a galaxy [Andromeda] looked like 25.4 million years ago. This is one thing that I wrote down at the beginning of the semester that I wanted to learn."

"The big bang theory because you always hear people say it, but I never knew what it actually was."

"I really like the Zen Pencils comic strip because it involves life in the universe."

"How everything in general is pretty much made up of metals/dirt, which sorta (not really) debunks my 'space is mystical' thing."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"I need a bit more clarification on the big bang theory, other than that everything was pretty straightforward."

"I was tripping out on that video that talked about why the space is black, so is it black because when we look at space we are actually looking at space in the past? Please go over this a bit."

"It is puzzling that we don't know if there is a true edge of the universe. And what happens if the universe has an edge? How does that affect our understanding of the universe?"

"Light years are a concept that continue to confuse me."

"Look-back time. And how do you calculate how far another galaxy is?"

"The 'gaps' between galaxies."

"Does hydrogen turn into the metals and how?"

"I am not understanding the differences between a halo and a disk as it refers to the Milky Way's different formations. They both seem the same to me."

"Trying to grasp the concept with an open mind as an infinite anything is hard to think of as well as that at one time there were no stars or anything is just hard to wrap my mind around."

"The Hubble law."

"The Hubble law, which sounded interesting, also kind of lost me a little."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [33%]
Metals (elements heavier than hydrogen and helium): increased [73%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	***** [5]
young stars that formed very recently.	********* [9]
(There is a tie.)	[0]
(Neither, as stars cannot have metals.)	[0]
(Unsure/guessing/lost/help!)	* [1]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [67%]
Helium in the sun's core: the sun [40%]
Carbon in your body: another star, in the past [40%]
Calcium in your bones: another star, in the past [53%]
Iron in your blood: another star, in the past [53%]
Gold and silver from mines: another star, in the past [33%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Is there an actual answer to what caused the big bang?" (Not yet, but asking what caused the big bang might be like asking "why does time run forward?" or "why isn't gravity both attractive and repulsive?")

"Will we learn more about the big bang theory?" (Yes, after the second midterm.)

"Could you please go over the difference between a halo and a disk as it refers to the Milky Way?" (Here's a visual explainer from the European Space Agency.)

"I really enjoyed this reading."

"I love this class!"

"We're coming up nearer and nearer to the end, I can't wait to see what else you have in store." (You'll see.)

"If the universe wasn't infinite, then would could be beyond it?" (If it turns out that the universe wasn't infinite, then if you started traveling outwards, you wouldn't keep going and going, but after a long time you would eventually return back to your starting point.)

Astronomy quiz archive: stellar evolution

Astronomy 210 Quiz 6, fall semester 2019
Cuesta College, San Luis Obispo, CA

Section 70158
Exam code: quiz06sOr6


Section 70158

0- 8.0 :
8.5-16.0 :	**** [low = 13.5]
16.5-24.0 :	******
24.5-32.0 :	************ [mean = 27.5 +/- 6.9]
32.5-40.0 :	************ [high = 36.5]

Section 70160
Exam code: quiz06NyQ7


Section 70160

0- 8.0 :
8.5-16.0 :	****** [low = 11]
16.5-24.0 :	****** [mean = 21.7 +/- 6.8]
24.5-32.0 :	*******
32.5-40.0 :	** [high = 33]

Astronomy quiz question: B5 main sequence star vs. M5 giant

Astronomy 210 Quiz 5, fall semester 2019
Cuesta College, San Luis Obispo, CA

A B5 main sequence star and an M5 giant could have the same:
(A) luminosity.
(B) size.
(C) temperature.
(D) (Two of the above choices.)
(E) (All of the above choices.)
(F) (None of the above choices.)

Correct answer (highlight to unhide): (A)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The B5 main sequence star has a smaller size and a hotter temperature than the M5 giant, but they could have the same luminosity.


Section 70158
Exam code: quiz05Sh0w
(A) : 22 students
(B) : 1 student
(C) : 0 students
(D) : 2 students
(E) : 1 student
(F) : 3 students

Success level: 77% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.63

Astronomy quiz archive: sun/spectra/star properties

Astronomy 210 Quiz 5, fall semester 2019
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz05Sh0w


Section 70158

0- 8.0   :
8.5-16.0 :	*** [low = 10.0]
16.5-24.0 :	*
24.5-32.0 :	********* [mean = 32.0 +/- 8.2]
32.5-40.0 :	******************* [high = 40.0]

Section 70160, version 1
Exam code: quiz05NpRm


Section 70160

0- 8.0   :
8.5-16.0 :	* [low = 16.0]
16.5-24.0 :	**********
24.5-32.0 :	***** [mean = 26.0 +/- 7.5]
32.5-40.0 :	****** [high = 40.0]

Online reading assignment: Milky Way history, big bang clues (SLO campus)

Astronomy 210, spring semester 2019
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"Black holes."

"The theory of how we know what the Milky Way looks like is particularly interesting to me. Just how we can understand what our surroundings in the universe are based off of what we can see is pretty amazing."

"Learning about what the universe is made of and how everything formed."

"I found it really cool how you said that we are all made of stardust. It's a cool idea."

"I think overall the big bang is very interesting, it's fun to learn where we came from."

"That we can tell how old a star is based on how much metal there is, like if it's an old star it's metal-poor but if it's a new star it's metal-rich."

"I think it's cool we came from stars. 'Everything is made of stardust.'"

"All the different kind of metals."

"To know that we are all made up of matter that originated from the universe itself is absolutely wicked."

"That the universe started pretty much with only hydrogen because that is not a lot of variety."

"I like the idea that we are essentially made up of stardust because it connects my sense of self and body to the great unknown of space."

"To learn that newer stars will be more metal-rich. I thought it would be the other way around, with older stars being more metal-rich, because that was just the way my train of thought went."

"The Milky Way being built up from absorbing small galaxies over time, the YouTube simulation was pretty cool."

"Something that I thought was really cool and kind of messed with my mind is that if we are looking at a star that is 1,400 light years away we aren't looking at how it looks now. We are actually looking at how it looked 1,400 years ago."

"I thought it was really cool how in the TEDTalk it talked about how light years work and that it takes 8 minutes for sunlight to reach us so when we see it we see what the sun looked like 8 minutes ago. When we see the Big Dipper were actually seeing what it looked like 80 years ago."

"Kipling's 'The Elephant's Child' story, because I have never heard of any part of that story and it was intriguing."

"The big bang theory."

"The big bang section. It was interesting to learn about some of the things we think are true about it!"

"All of the matter here on Earth (and space) originally came from stars. Everyone is connected through old roots."

"I loved the videos from Minute Physics! I'd never heard of them before this course, and am very interested to check out more of their stuff!"

"The big bang theory is interesting to me. I find it interesting because it explains how life on Earth began."

"I found the entire presentation very interesting because we take so many classes about the history of Earth but I have never thought about the history of a galaxy."

"That the claim that there is 'no center of the universe' is an absolute, and is not possible to make that claim seeing as how we haven't found the boundaries of the universe, scientists just assume that it is boundless?"

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Black holes, still."

"How the universe began with just hydrogen. What created the hydrogen?"

"How did all of the metals get here?"

"The hydrogen/metals section. I skimmed through the section and couldn't find the answers to the questions below."

"Understanding the metallicity of stars is confusing to me. If stars are fussing hydrogen and run out of energy at iron then how are they 'metallistic?'"

"I found the production of elements to be kinda confusing."

"Monolithic collapse or how the Milky Way changed from spherical to flattened shape, was confusing to me."

"Light years, distances..."

"Lookback time seemed like an odd concept. Why are we looking into the past? Does it have to do with older stars?"

"So the night sky is dark but isn't? this was confusing to me because if the universe is forever expanding does that mean it will eventual all be bright and what would happen to the dark matter?"

"I want to go over more about the big bang."

"What is causing galaxies to move away from each other? I know, we are far from galaxies, but I am wondering how they are separating."

"Something I found interesting and confusing was the Hubble law and that everything is expanding."

"Learning about why galaxies move away or towards us was a bit confusing. I think I just need it explained in class to really grasp the idea."

"From the video 'Why is it Dark at Night,' I understand that it takes time for light to reach us as it travels through space. So are there places in the universe such as the earliest point where the big bang happened where space would be bright?"

"The Hubble constant. Is everything in space moving at the same speed?"

"The space between galaxies and how the space between galaxies actually expands. I have found half of this class to be confusing. My mind is much more in tune with art and music rather than science and math."

"The big bang was confusing."

"Nothing specifically."

"I still need to read this material."

"I'm honestly just kinda confused about all of it so some review would be helpful."

"I didn't find anything confusing enough to put in this box."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [64%]
Metals (elements heavier than hydrogen and helium): increased [71%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	****** [6]
young stars that formed very recently.	***************** [17]
(There is a tie.)	* [1]
(Neither, as stars cannot have metals.)	[0]
(Unsure/guessing/lost/help!)	**** [4]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [46%]
Helium in the sun's core: the sun [32%]
Carbon in your body: another star, in the past [43%]
Calcium in your bones: another star, in the past [46%]
Iron in your blood: another star, in the past [46%]
Gold and silver from mines: another star, in the past [50%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"I would love a little more lecture for this section as I didn't get a chance to read in detail yet."

"What are some of the reasons some people don't believe in the big bang?" (You don't have to believe in the big bang, you just have to understand how to interpret the evidence. Other people's interpretation may differ. Some other people may not bother even looking at the evidence.)

"Do you believe that the universe is infinite?" (Well, the universe is finite in the sense that because looking further out in space means that you are looking further back in time, and since time "began" at the start of the big bang about 14 billion years ago, then there is an edge in time to the observable universe, about 14 billion years out away from us in all directions. So I'll go with that.)

"If the universe started out with just hydrogen, who/what are the hydrogen's mommy and daddy? (The big bang. Well, actually just after the big bang (energy) cooled down enough for protons and electrons to form, which is what hydrogen is made of (one proton and one electron).)

"I couldn't figure out where gold and silver originate from, but I'd love to know." (Star poop. Gold and silver (and everything else heavier than helium) are by-products of stars consuming hydrogen for fusion, forming metals, and then exploding, casting all that stuff out the rest of the universe for new stars (and planets) to form. So basically, star poop.)

"Explain the Hubble law, thanks :)"

"I thought reading about the big bang was interesting because being raised Catholic I don't know a lot about it." (Interestingly enough, it was a Catholic priest (and scientist) who was the first to propose the big bang theory.)

"Please help."

"Very happy to have done better on the second midterm than the first."

"I killed the second midterm."

"Can we go over the final exam material every class in preparation for the final exam?" (We are doing that, in the sense that the last two weeks of the semester use all the concepts we've learned earlier.)

"How was your weekend?" (Mrs. P-dog and I celebrated Sinkhole de Mayo. How was your weekend?)

Online reading assignment: Milky Way history, big bang clues (NC campus)

Astronomy 210, spring semester 2019
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"There was less metal in the universe and now there is more."

"How telescopes act as time machines. I never really knew about finite speed of light in relations to using a telescope, so this really grabbed my attention."

"The further away we look the further back in time we look."

"Lookback time, as it gives us a true scope of how little we know about what is truly going on light years away from us."

"The three-dimensional representation of the galaxies is terrifyingly interesting because the further we look out into space, the less thing we find to look at due to the lookback time and not seeing the edge of space but the edge of time."

"All the images of the galaxies were super-interesting. They looked so amazing I went and bought a calendar of it :)"

"The big bang and the different clues about it."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Dark matter forever confusing."

"First generation stars being metal-poor."

"I found metallification from stars to be confusing because I was uncertain how the metals would be dispersed from the core unless done via a supernova."

"How do we know specifically where the elements that make us up are from? I did not find this information in the textbook or slides."

"The Hubble law. I would definitely appreciate some review on this one because I honestly feel kind of lost about it."

"The cosmic expansion of space and not galaxies confuses me, because what's causing the expansion?"

"Where would the energy come from in the big bang theory?"

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [63%]
Metals (elements heavier than hydrogen and helium): increased [77%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	******** [8]
young stars that formed very recently.	********* [9]
(There is a tie.)	[0]
(Neither, as stars cannot have metals.)	[0]
(Unsure/guessing/lost/help!)	***** [5]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [50%]
Helium in the sun's core: the sun [50%]
Carbon in your body: another star, in the past [50%]
Calcium in your bones: another star, in the past [41%]
Iron in your blood: another star, in the past [50%]
Gold and silver from mines: another star, in the past [27%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Metals produced by stars is from fusion to heavier elements, why was only in trace amounts?" (Since fusion only occurs in the cores of stars, and most of the hydrogen in the outer layers don't participate in this process (other than pressing down on the core to provide the high pressures for fusion), then only a small amount of the hydrogen in a star ever gets fused into heavier elements.)

"So the metals produced by stars, is that from fusion to heavier elements?" (Yes.)

"Hypothetically, if someone went to a place super-far away in our galaxy, could they see dinosaurs on Earth or other possible lifeforms elsewhere?" (Theoretically, yes, but they would need a super-resolving power telescope to see that much detail from far away.)

"How did the 'big bang' form?" (Nobody really knows. But at least we have evidence that it did occur.)

"Did you celebrate Cinco de Mayo?" (Mrs. P-dog and I actually celebrated Sinkhole de Mayo.)

Do you teach over the summer? What are you doing for summer break?" (I don't teach during the summer, so Mrs. P-dog and I usually go camping on extended road trips for a few weeks.)

"Random question. Would you ever buy a Tesla?" (No. Where Mrs. P-dog and I go camping, there are no charging stations.)

"Do you believe in astrology?" (Nope.)

Astronomy quiz archive: stellar evolution

Astronomy 210 Quiz 6, spring semester 2019
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz06nD4d


Section 30674

0- 8.0 :
8.5-16.0 :	**** [low = 9.0]
16.5-24.0 :	************
24.5-32.0 :	******* [mean = 24.7 +/- 7.9]
32.5-40.0 :	******** [high = 40.0]

Section 30676, version 1
Exam code: quiz06s33N


Section 30676

0- 8.0 :	* [low = 7.5]
8.5-16.0 :	*****
16.5-24.0 :	************** [mean = 23.5 +/- 6.5]
24.5-32.0 :	*****************
32.5-40.0 :	**** [high = 36.5]

Astronomy quiz archive: sun/spectra/star properties

Astronomy 210 Quiz 5, spring semester 2019
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz05NiR0


Section 30674

0- 8.0   :
8.5-16.0 :	**** [low = 11.0]
16.5-24.0 :	***********
24.5-32.0 :	****** [mean = 26.2 +/- 8.7]
32.5-40.0 :	********** [high = 40.0]

Section 30676, version 1
Exam code: quiz05S4re


Section 30676

0- 8.0   :	** [low = 2.5]
8.5-16.0 :	**
16.5-24.0 :	********
24.5-32.0 :	*********** [mean = 27.6 +/- 9.2]
32.5-40.0 :	*************** [high = 40.0]

Online reading assignment: Milky Way history, big bang clues (SLO campus)

Astronomy 210, fall semester 2018
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"This suggests a simple 'monolithic collapse' model of Milky Way evolution, where hydrogen for star formation gradually migrated from a spherical shape to its current flattened disk shape. This model is perhaps too simple."

"I think it is mindblowing that we are able to see (with the naked eye) light that is over 2.5 million years old. Literally like a time machine that see things we can't touch, but just admire. It makes me feel really small and insignificant in the expanse of our universe."

"One light year is crazy to me, let alone how far away everything is based on light years. It's mind-blowing."

"The thought that telescopes are technically time machines is really abstract."

"That at the start of the universe was primarily hydrogen interesting because that is how the all of the stars started to form."

"Learning about how the universe is expanding. Also how scientists used this information to look into the past to find out how old the universe is."

"I found the 'edge of time' to be interesting. The thought of the universe having a finite age isn't something I thought of before. We always want to think of something having an end, but the universe is expanding."

"That all galaxies are fleeing away from the Milky Way."

"That the big bang occurred everywhere; before I assumed it happened in a specific location."

"The part concerning the infinity of space really interests me it always has. Is there and end to it all? If there is whats beyond the end of space? It really gets me."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Lookback time was confusing at first, but having the concept of light years explained cleared this up."

"Understanding which stars have more or less metals then others."

"Metal-rich versus metal-poor stars and how this relates to their location in the galaxy."

"Need some review over what produces a specific kind of element. I couldn't find it within the blog lecture, but I'm sure it's there. Just need some further review."

"How the stars and later type II supernovas created metals in its core if it didn't have any metals to start out with."

"The difference between population I stars and population II stars? What confuses me is how the ages of population I stars can be older than population II stars?"

"I find it confusing to understand how the universe is expanding everywhere. What is causing this?"

"Metallicities."

"Wow is there an 'edge of time.' and what is beyond that?"

"I am confused if we can only see 14 billion light years away as that is what they predict how old our universe is."

"How can astronomers and other scientist say the Universe and all of the things within it are a certain age? The textbook states, the ages of particular parts of the universe are 'somewhat uncertain,' but scientist still claim their theories are correct without any real, provable evidence."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [47%]
Metals (elements heavier than hydrogen and helium): increased [95%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	*********** [11]
young stars that formed very recently.	******** [8]
(There is a tie.)	[0]
(Neither, as stars cannot have metals.)	[0]
(Unsure/guessing/lost/help!)	[0]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [64%]
Helium in the sun's core: the sun [32%]
Carbon in your body: another star, in the past [58%]
Calcium in your bones: another star, in the past [47%]
Iron in your blood: another star, in the past [47%]
Gold and silver from mines: another star, in the past [32%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Is time travel really real?" (No, but looking back in time is real.)

"Look-back time is absolutely insane. How are we seeing Deneb as it was 1,400 if we are looking in the present? Or Andromeda, how are we seeing the stars from millions of years ago? I'm so confused? HELP P-DOG!"

"How far away is the most distance star or galaxy we can see and if it is more that 13.8 billion light years away how can we see it?" (Since as we look further and further out, we see things further and further back in time, so if we far out enough, we'll eventually be looking so far back in time that we will see what the universe was like before the first stars were even born; this is about 14 billion light years away, as it was 14 billion years ago.)

"I was a little confused with where the elements were produced."

"Please explain the relationship between population I and II type stars."

"Why is the universe expanding?"

Online reading assignment: Milky Way history, big bang clues (NC campus)

Astronomy 210, fall semester 2018
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 questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"I found the topic of when the universe and how it began very interesting; I like reading about the theories and wonder if they are 100% accurate."

"How we can look back into time in a certain manner of speaking by observing the stars light that is coming from light years away. The fact that we are not seeing the object as it is but as it was from the amount of light years it takes to get here."

"Light is like time travel but not. Light from other areas may not currently exist today but it did years ago."

"How old our galaxy is, and how they could determine this was interesting because it's such a large span of time that is really hard to imagine."

"The early universe started out with basically just only hydrogen, and the first-generation massive stars then gathered this hydrogen and promptly got to work."

"That elements humans are made out of came from stars. I never realized were that closely connected to space."

"The iron, carbon, and calcium in us is as old as like everything."

"What I found cool was that the universe keeps expanding; I thought it was interesting because it makes me question about other life forms."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"How metals have formed over time."

"The origins of elements in the universe."

"Olbers' question about the edge of the universe."

"How from the big bang planets and suns and galaxies formed."

"'Big bang'--I'm unclear as to what is being referred to exactly: if it's a process, or how it works overall."

"The Hubble law--I did not quite understand it and would like further explanation on it."

"Most of this reading I found confusing, didn't really understand or knew where to find the answers :("

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)

Hydrogen: decreased [31%]
Metals (elements heavier than hydrogen and helium): increased [54%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).

extremely old stars that formed a long time ago.	***** [5]
young stars that formed very recently.	****** [6]
(There is a tie.)	[0]
(Neither, as stars cannot have metals.)	* [1]
(Unsure/guessing/lost/help!)	* [1]

Indicate what produced these elements.
(Only correct responses shown.)

Hydrogen in the sun's core: the very early universe [54%]
Helium in the sun's core: the sun [38%]
Carbon in your body: another star, in the past [38%]
Calcium in your bones: another star, in the past [45%]
Iron in your blood: another star, in the past [38%]
Gold and silver from mines: another star, in the past [38%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Can we learn about black holes?" (We already did; but now we're going to learn about the big bang.)

"Do you think we'll one day actually be able use this concept of look-back time to make time travel (the science fiction kind) actually possible?" (The light that travels to us from distant objects is "old," and allows us to see what was going on at the moment that light started out from its source. The distant source of that light is living in the present, though, and there (conventionally) is no way to travel to that distant source and wind up in its past, even though we can see how it was in the past.)

"As I have always heard that the universe is ever expanding. Could there be galaxies forming in between those spaces and the light just hasn't reached us yet?" (The space between galaxies is empty (otherwise we wouldn't be able to see other galaxies), so no gas or dust is there for new stars and planets (and galaxies) to form. That stuff only happens within galaxies.)

"How was your Thanksgiving? (Eh, it was okay. I'm fine with okay; for me okay is pretty awesome. How was your Thanksgiving?)

Astronomy quiz archive: stellar evolution

Astronomy 210 Quiz 6, fall semester 2018
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz06SeR3


Section 70158

0- 8.0 :	* [low = 8.0]
8.5-16.0 :	*******
16.5-24.0 :	************ [mean = 22.1 +/- 7.8]
24.5-32.0 :	**********
32.5-40.0 :	**** [high = 40.0]

Section 70160, version 1
Exam code: quiz06SNn5


Section 70160

0- 8.0 :	* [low = 8.0]
8.5-16.0 :	*****
16.5-24.0 :	****** [mean = 20.7 +/- 6.9]
24.5-32.0 :	*****
32.5-40.0 :	* [high = 33.0]

Astronomy quiz question: smallest star?

Astronomy 210 Quiz 5, fall semester 2018
Cuesta College, San Luis Obispo, CA

Which star is the smallest?
(A) A0 white dwarf.
(B) B5 main sequence star.
(C) K5 giant.
(D) M0 main sequence star (red dwarf).
(E) (There is a tie.)

Correct answer (highlight to unhide): (A)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The K5 giant is largest, followed by the B5 main sequence star, M0 red dwarf, and the A0 white dwarf is smallest.


Section 70160
Exam code: quiz05Oor7
(A) : 9 students
(B) : 1 student
(C) : 1 student
(D) : 5 students
(E) : 1 student

Success level: 55% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

Astronomy quiz question: hottest star?

Astronomy 210 Quiz 5, fall semester 2018
Cuesta College, San Luis Obispo, CA

Which star is the hottest?
(A) A0 white dwarf.
(B) B5 main sequence star.
(C) K5 giant.
(D) M0 main sequence star (red dwarf).
(E) (There is a tie.)

Correct answer (highlight to unhide): (B)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The B5 main sequence star is the hottest, followed by the A0 white dwarf, the K5 giant, and the M0 main sequence star (red dwarf) is the coolest. Instead of using the H-R diagram, the OBAFGKM mnemonic can be used to determine the temperatures of these stars from their spectral type.


Section 70158
Exam code: quiz05T3rA
(A) : 2 students
(B) : 0 students
(C) : 0 students
(D) : 20 students
(E) : 0 students

Success level: 78% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

Astronomy quiz question: F0 supergiant vs. G5 giant

Astronomy 210 Quiz 5, fall semester 2018
Cuesta College, San Luis Obispo, CA

An F0 supergiant has a ___________ than an G5 giant.
(A) brighter luminosity.
(B) larger size.
(C) hotter temperature.
(D) (Two of the above choices.)
(E) (All of the above choices.)
(F) (None of the above choices.)

Correct answer (highlight to unhide): (E)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The F0 supergiant has a brighter luminosity, larger size, and a hotter temperature than the G5 giant.


Section 70158
Exam code: quiz05T3rA
(A) : 2 students
(B) : 0 students
(C) : 4 students
(D) : 6 students
(E) : 21 students
(F) : 0 students

Success level: 66% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.38