Sketchbook: stellar evolution

See if you can identify everything in this doodle.

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]

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.

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 car example to be really interesting. It's cool how we can relate real life things to this subject."

"How the stars can live off of helium after they have depleted all of their hydrogen."

"That helium fuses into heavier elements when it reaches a higher temperature of 100,000,000 K. Chemistry is my favorite subject and I was just very intrigued at that."

"Supernovas are fascinating because they are one of those 'doomsday' events that the sci-fi genre tends to romanticize."

"How in a binary star system, a dying star will begin 'eating' the fuel of its companion star. And if it 'eats' too quick it will explode and kill itself and its partner."

"How sad some white dwarf stars are alone. It's pretty depressing that they starve to death and die alone."

"That when medium-mass stars die they become white dwarfs, and then with a companion star go on to either become a nova or a type Ia supernova."

"The way a white dwarf can suck the hydrogen from a companion star is amazing."

"The death process of the stars, especially, the type II supernova. I did not know anything about how stars die, why they die, and what they become after death."

"Core implosion/explosion is very fun to learn about. I can imagine the outer layers of the star being gravitationally forced to crush the inner core. I can imagine that type II supernova star explosion being fairly colorful and dusty."

"I spent almost my entire high school career researching the death-cycle of stars for my senior project. WAY cool."

"That it would take forever watch something get into the black hole. And the spaghettification effect."

"How black holes can make bipolar jets! That's cool."

"I was always curious as to how black holes formed! They are just so... ominous. I would not want to get near one--they're freaky!"

"I thought this whole lesson was super-interesting, guess I'm goth-ier than I realized haha."

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

"Why a Hummer and a SmartCar can travel the same distance if a Hummer has a larger tank and a SmartCar has a smaller tank."

"Corresponding the correct end-of-life stage to the correct main-sequence star is a bit confusing at first because white dwarfs have technically low mass, but they become one after their medium-mass star depletes its hydrogen and becomes a giant that turns into a white dwarf after all its energy has been exerted."

"Why do massive stars eat anything they can to survive but smaller stars won't eat as much junk?"

"I need more explanation on a star's death and the phases the star takes as it dies."

"How it is possible for a white dwarf (with a companion star) to either flash-fuse or just simply explode. How can it do one or the other? Wouldn't it just do one every time?"

"As much as black holes intrigued me, they also confused the hell out of me. Trying to understand the physics of it all was pretty difficult."

"Time slowing when approaching a black hole's event horizon."

"I'm having trouble wrapping my head around the idea of black holes--why they can't be seen, event horizons, space-time, etc."

"Why the space-time grid is always depicted as a flat surface. I just don't get we they do that. Is it to make it easier to conceptualize?"

"When talking about black holes in space, I understand that we would be able to feel a black hole because of the gravitational pull inward toward it. I'm confused about how the black hole effects space-time."

"A bit of everything since it's all so much to take in."

"Nothing particularly was confusing."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"The fuel usage for a SmartCar is way lower than the fuel usage of a Hummer, but a Hummer has way more fuel available to it than the SmartCar."

"A Hummer has a larger tank with lower gas mileage while the SmartCar has a smaller tank with higher gas mileage. These factors balance each other out between the two cars and give them both the same traveling distance."

"The Hummer could have a bigger gas tank than the SmartCar. And the SmartCar would have better gas mileage."

"The Hummer can hold a lot of gallons of gas, but it burns through it very quickly (bad gas mileage). A SmartCar doesn't hold very many gallons but burns through it very slowly (good gas mileage)."

"I'm kind of confused on how to explain this. It didn't make sense to me at all."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [92%]
Neutron star: massive main sequence star [76%]
White dwarf: medium-mass main-sequence star [80%]
(No stellar remnant observed yet): low-mass main-sequence star [72%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [88%]
Type Ia supernova: medium-mass main-sequence star [92%]
Nova: medium-mass main-sequence star [56%]
Low-mass main-sequence star: (no explosion possible) [56%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	* [1]
hours.	** [2]
days.	* [1]
a year.	[0]
many years.	* [1]
forever.	***************** [17]
(Unsure/guessing/lost/help!)	*** [3]

The first rule of astronomy class is...

"Show interest in space."

"Observe the world around you."

"To actually show up and attend class!"

"Don't procrastinate."

"Question everything you thought you knew."

"Read the syllabus and get your starwheel."

"I'm not too sure. Show up early? Wear old clothes? Bring a sledgehammer?"

"A foot-measuring device is for feet only."

"I feel like this was a trick question and I searched the text for it, but ultimately just ended up confused. The first rule is to learn to the best of your abillity?"

"You do not talk about astronomy class."

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

"I need a lot of explanation on the main sequence stars and explosions, plus how the lifetimes work."

"Dying stars are cool."

"Was our solar system (planets, asteroids, etc.) created by another star or from our sun? If by a different star, where is that star now?" (Anything other than hydrogen in our solar system was created by massive stars that exploded a long time ago (we don't know where those first-generation stars that lived and died are anymore). Then when our sun starting forming out of unused hydrogen from those previous stars, it gathered up the elements created by those stars around it to make the planets. #deepthoughts)

"Talk about black holes, I can't get enough."

"'Spaghettification' is my new favorite word."

"Do you like Star Wars? (Well, probably just the original trilogy. And maybe Rogue One.)"

"What is "nothing"? Can there be such a thing? I just watched '2013 Isaac Asimov Memorial Debate: The Existence of Nothing' and now my brain hurts and I'm not satisfied with the answers given there." (Now you're making my brain hurt. #deepthoughts)

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.


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.

"How a low-mass star will take much longer to run out of hydrogen to fuse. How does it take longer, since it's smaller? "

"How a Hummer and SmartCar are able to travel same distance even with the Hummer having a larger tank."

"The lifetimes of the stars. I just find it cool how it's the bigger stars that burn out and die off the quickest compared to the small stars who live on for much longer."

"In a long time the sun will eventually expand into a red giant and that is when Earth will come to an end."

"That a star's mass determines what happens when the star runs out of fuel, and what type of 'corpse' it will become after its death."

"That when a star is about to die it goes into 'starvation' mode."

"Learning more about stars like our own really puts our existence into some perspective."

"That different mass stars die different ways, because I had just assumed that they would just stop glowing, but I was way wrong."

"The types of supernovas/novas, because those were cool images."

"Black holes."

"Black holes are invisible, kinda ominous and scary, but interesting nonetheless."

"The escape velocity of a black hole blows my mind that even light cannot escape."

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

"How convection currents work internally in the stars."

"I'm confused about binary systems and how they keep going even after the nova that occurs from the white dwarf."

"I'm not grasping the different types of supernovas/novas."

"The lighthouse model! What is it trying to explain?"

"Black holes and neutron stars. I don't know the models made a little sense but I think spending a little more time on it and further explanation on it that would help because I am a little lost."

"How a black hole works."

"Nothing in particular."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"The Hummer H2 has a bigger gas tank but uses it faster. The SmartCar has a smaller gas tank and uses it slower."

"The Hummer has lower mileage than the SmartCar but, it has a bigger fuel tank."

"It's possible because the SmartCar has better fuel efficiency with its smaller tank."

"I honestly don't know; I'm slightly confused."

"Don't know yet."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [76%]
Neutron star: massive main sequence star [59%]
White dwarf: medium-mass main-sequence star [53%]
(No stellar remnant observed yet: low-mass main-sequence star [35%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [88%]
Type Ia supernova: medium-mass main-sequence star [82%]
Nova: medium-mass main-sequence star [35%]
Low-mass main-sequence star: (no explosion possible) [53%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	** [2]
hours.	* [1]
days.	[0]
a year.	[0]
many years.	* [1]
forever.	********** [10]
(Unsure/guessing/lost/help!)	*** [3]

The first rule of astronomy class is...

"Persistence?"

"Ask questions?"

"Earth is flat?"

"To build telescopes?"

"Come to each and every class?"

"Dome prepared and ready to learn?"

"Look up at the stars, because that is where the answers are?"

"You do not talk about astronomy class.' (Fight Club, 1999)"

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

"How are cars related to astronomy?"

"For a medium-mass star, how come the convection current doesn't work in the similar way a low mass star works?" (Convection is a surface effect for a star, so for a medium-mass or massive star, convection (the "miso soup effect") is right at the "skin" of those stars. However, for a low mass star, it is so small that the "skin" and core are basically touching, such that the convection currents are able to affect the core.)

"What is space-time and how can gravity affect it?"

"I'd like to go over black holes a bit more."

"Will we get into black holes more or will we just get a brief talk about them?

"Have humans ever sent anything into a black hole?" (No, but we have observed stars being shredded apart as they get too close, and their material falls in towards black holes.)

"Can you please go over these slides in class, there was a lot, thank you."

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]

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.

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 think that everything in this presentation is interesting. Especially the pictures and GIF animations provided of what the life stages look like. It's not something a student outside of the astronomy class would see and understand."

"Comparing low-mass and medium-mass stars to a SmartCar and a Hummer. It made the analogy easier to remember."

"I found the H2 versus Smartcar example a great way to put this section into perspective. Not having great mileage but having the capacity to compensate for it."

"That a lower mass star can survive substantially longer than a larger mass star."

"I like the refrigerator analogy and 'star-vation.' It helped me understand the stages in which order a star will use certain fuels."

"I liked your refrigerator analogy about stars having to eat helium after all the hydrogen is gone because a star's got to eat, right?!"

"Stars from about the size of the sun could turn into giant stars and massive stars could potentially become supergiants. Red dwarfs are fully convective meaning that their life expectancies are extended."

"How if you open mouth breathe on your hand it will be warm, but if you purse your lips it will be cool. I found that it made the information easier to understand."

"That a medium-mass star becomes a giant."

"How different mass stars die differently."

"I found it interesting that the more massive the star the longer it keeps fusing. So after hydrogen it fuses helium into carbon, and if its massive it keeps going. I didn't know stars fused beyond hydrogen."

"That the energy generated in the core of a star is what opposes gravity and supports the star."

"I thought the information about how stars die was interesting because I didn't know the many ways they could go."

"That an entire star's life revolves around this single force that is gravity. The star is using gravity to create more energy for itself from its core to continue living, and at the very end, it has a life or death battle with gravity where it can either lose and become consumed in darkness, (black hole) or continue in peace in ultimate stability (neutron star)."

"I found it interesting that there are different types of supernovas: type Ia and type II."

"Massive star death. Probably one of the coolest things about the universe. Who doesn't like explosions?"

"Black holes and the effect it has on spacetime and what is around it. The fact that you can't see it but you can feel it is crazy."

"Black holes are very interesting because we do not know what they do and they are scary."

"Black holes, because what is even their purpose?"

"To see how there is a 'black hole' in Lake Berryessa. I don't know how to swim and just looking at the image makes me scared."

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

"I didn't understand the Hummer H2 and SmartCar question."

"There wasn't anything that was too confusing. At first I was a little lost with the car example."

"The medium-mass star stages. I'm a bit fuzzy on how a star that is losing its fuel source is increasing in size. Normally in most situations its the other way around. So I am curious to see how this works."

"The different types of (super)novae."

"Binary system explosions."

"Black holes, because they seem so complicated, how could we ever really comprehend what they actually are and do."

"How black holes work and what happens when something gets sucked into it."

"The event horizon of a black hole. I am unsure what the event horizon is even after reading the definition in the textbook I am still confused."

"Black holes were confusing. Everything about that section just went over my head."

"I can't really wrap my head around a black hole's time dilation. How do we know this exists?"

"I have a lot of questions. I'm sure as I listen to you explain it that will help though. I learn by listening."

"A little bit of everything was confusing. I got the main parts but some of it was slightly confusing."

"I did not find anything particularly confusing."

"Almost everything."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"Because the Hummer H2 has such low gas mileage it requires a bigger gas tank to get farther. The SmartCar has better gas mileage so it can get away with a smaller tank. One variable is increased while the other is decreased making the total distance even."

"The Hummer and the SmartCar have the same range but two different variables. The Hummer has a lower mpg and a larger gas tank. The SmartCar on the other hand has a high mpg with a small gas tank. Because the SmartCar has a higher mpg, it allows it to use fuel more efficiently. While the Hummer is not fuel efficient, it has to compensate by having a large fuel tank. But ultimately, both vehicles have the same range."

"They can travel the same distance because whilst the H2 having bad gas mileage, it makes up for it by having a large fuel tank to compensate."

"The Hummer has more gas in the car but it burns through it faster where the SmartCar can hold less gas but uses it more efficiently."

"I really don't understand this question."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [64%]
Neutron star: massive main sequence star [58%]
White dwarf: medium-mass main-sequence star [48%]
(No stellar remnant observed yet): low-mass main-sequence star [42%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [76%]
Type Ia supernova: medium-mass main-sequence star [70%]
Nova: medium-mass main-sequence star [42%]
Low-mass main-sequence star: (no explosion possible) [55%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	*** [3]
hours.	* [1]
days.	* [1]
a year.	* [1]
many years.	*** [3]
forever.	***************** [17]
(Unsure/guessing/lost/help!)	******* [7]

The first rule of astronomy class is...

"I don't know."

"Study?"

"Keep looking up?"

"Be intrigued by space?"

"Read the textbook materials and show up to class?"

"Pay attention?"

"You cannot see black holes by themselves?"

"To ask questions?"

"Prepare?"

"To have fun while learning?"

"To know the difference between astronomy and astrology?"

"Pay attention and do your reading because it's difficult?"

"Always bring a towel?"

"We have a rule?"

"There is no astronomy class?"

"Don't talk about astronomy class."

"Tell all your friends about astronomy class?"

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

"I shared with my sister the house party model. She laughed!"

"I found the reading to be very confusing this week! The presentation slides somewhat helped."

"I am confused at the death of stars and their end-of-life stages. Would it be possible to go over those in class?"

"I would like to learn more about how gold is formed from a supernovae."

"What would be a dumbed-down version of explaining a black hole?"

"Could we go over the black holes section in more detail?"

"I'm good but thank you! Is there going to be another study session before the next midterm? (Yes.)

"Can we review what is going to be on the next quiz and exam in our next classes? (We will.)

"How much will we review as a class for the final?!?!?!?!?!" (The study guide for the final exam will be posted soon. But first get through the next quiz and the second midterm.)

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.


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 fact that low-mass stars take billions of years to die and spend so much time as a main sequence star. To think something like that has lived for so long is pretty cool to think about."

"How the Hummer H2 and SmartCar comparison was used to describe main-sequence lifetimes of stars, it made the material very memorable."

"The comparison between stars and cars."

"How giants cool as they expand. I tried the trick of blowing air on my hand the two different ways and it helped me understand what was being said more."

"The discovery of how stars will undergo 'star-vation' was interesting to me; seeing how stars can almost recycle the atoms they created until they are no longer usable."

"How massive stars undergo type II supernovae explosions."

"That black holes are massive. This is interesting to me because they seem like they would be empty thus have lower mass."

"That tidal forces would make traveling through black holes really hard to do, even if it worked because it would stretch the body, and you would probably die."

"That you can't see a black hole."

"No idea."

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

"How astronomers know how much mass objects have. This is confusing because it is not like we can ever visit these things, they just know."

"Life spans of different stars."

"The different star deaths kind of confused me, not too much, though. I just got them confused at times."

"I was a little confused on how medium mass stars die. I think I understand the process, but would greatly benefit from reviewing it."

"Death of medium mass stars."

"The picto-quiz part of the medium mass stars and how to tell which stage is which."

"The different categories of (super)nova explosions. I'm not sure how they differ and it would be nice to get some more clarification on them."

"Pulsars."

"I thought understanding the concept of black holes to be confusing. The gravitational field that surrounds black holes, the horizons, tidal forces, and gravitational redshift. I guess it wasn't really confusing because the book was pretty straightforward, but I'm just having a hard time wrapping my head around the idea of it all."

"That you can't see a black hole."

"How the Event Horizon Telescope was able to see the black hole. When will they be able to see a black hole starting to form and how will they be able to catch it the right time?"

"Nothing particularly confusing, pretty easy to follow."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"Because the SmartCar is more fuel efficient it uses less gas and because the Hummer H2 isn't as fuel efficient, it has a bigger gas tank to make up for its lack of efficiency."

"Because although the SmartCar has a smaller fuel tank, it also requires less fuel to run. On the other end, the Hummer requires more gas, and has a larger fuel tank to compensate for it."

"The SmartCar engine holds a smaller amount of gasoline but does a better job of efficiently using it whereas the big H2 burns up gasoline much quicker."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [88%]
Neutron star: massive main sequence star [38%]
White dwarf: medium-mass main-sequence star [50%]
(No stellar remnant observed yet: low-mass main-sequence star [46%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [88%]
Type Ia supernova: medium-mass main-sequence star [73%]
Nova: medium-mass main-sequence star [38%]
Low-mass main-sequence star: (no explosion possible) [66%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	* [1]
hours.	[0]
days.	* [1]
a year.	* [1]
many years.	** [2]
forever.	****************** [18]
(Unsure/guessing/lost/help!)	*** [3]

The first rule of astronomy class is...

"Ask questions?"

"To call you P-dog?"

"Be engaged? Don't be disrespectful? Don't eat the nebulas even though they look like cotton candy?"

"Listen to P-dog if you want to be a successful human and know more about astronomy related topics and stuff?"

"I feel like I am missing something because I do not know how to answer this at all."

"Always look up?"

"Study?"

"Buy your own starwheel?"

"Go to class?"

"Do the online reading assignments? "

"To never procrastinate?"

"I honestly have no idea. Did I miss this in class?"

"You do not talk about astronomy class."

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

"It's funny to talk about Hummers and SmartCars because in high school I drove a SmartCar--it was embarrassing."

"Is there an actual first rule to astronomy class, or was I absent the day we went over it? "

"What is the first rule of astronomy class?"

"Will we discuss the first picture taken of the black hole?"

"What would happen after two black holes collide?" (There would be an even bigger black hole.)

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]

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.


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 way that a massive star dies in supernova. How it all implodes first then explodes is amazing. how all that energy is sucked in then bounced off into space. I'm sure it is a real awesome thing to witness."

"How two twin stars can be born but have different rates because of their masses."

"Stages of life stars go through. Like what happens before, during, and after."

"Differences between the three types of novae: nova, type Ia supernova, and type II supernova."

"Black holes! I thought it was cool how it's kind of like the Lake Berryessa dam intake but obviously much more complex."

"Learning about black holes since I have no idea what they really are or how they work."

"The fate of the sun and the stars, because now I'm curious if the universe could remake what we have now before they all die."

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

"How stars are not like cars?"

"Evolution of binary system stars because I'm not sure about the transferring of mass."

"I would just like a review of how binary pulsars work."

"Black holes seem pretty confusing like how time and space is messed up."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"One has a larger tank then the other, although the rate at which they use gas is different as well. One uses it quicker then the other."

"The SmartCar will use it smaller amount of fuel more economical. It will burn its fuel at a slower rate thus be able to travel the same distance as a larger Hummer."

"I need to read the material."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [90%]
Neutron star: massive main sequence star [40%]
White dwarf: medium-mass main-sequence star [50%]
(No stellar remnant observed yet: low-mass main-sequence star [40%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [70%]
Type Ia supernova: medium-mass main-sequence star [10%]
Nova: medium-mass main-sequence star [80%]
Low-mass main-sequence star: (no explosion possible) [40%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	** [2]
hours.	* [1]
days.	[0]
a year.	[0]
many years.	** [2]
forever.	**** [4]
(Unsure/guessing/lost/help!)	* [1]

The first rule of astronomy class is...

"Do your reading and follow the stars?"

"Show up prepared?"

"Do the reading?"

"Try?"

"Acquire knowledge?"

"Come to class?"

"To have fun?"

"Show up with a positive attitude?"

"Do your homework?"

"You do not talk about astronomy class."

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

"Thank you for making the slides and class interesting enough that it keeps me intrigued."

"I still don't understand why stars cannot pull more hydrogen from the space around it to feed itself for much longer than it does?" (The solar winds from a star during its main sequence (hydrogen fusion) lifetime typically pushes away any hydrogen nearby, clearing the space around it. However, that star can be fed by a comparing star as that companion star expands into a giant or subsequently a planetary nebula, as those hydrogen layers are pushed outwards from it to feed that star.)

"When a star explodes, the outer shell of the star is shed into interstellar space. Since there would only be elements from fusion no heavier that iron, where would a protostar and ultimately its solar system get any heavier elements?" (Even though fusion to produce elements heavier than iron requires energy instead of releasing energy, in a type II supernova explosion as the shell implodes and explodes there is lots of extra energy that can enable fusion to go past iron.)

"Nothing to ask this week."

"I love learning about black holes."

"Give me time. I'll catch up."

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (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 evolution of medium-mass stars, massive stars, neutron stars and black holes.

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 thought it was interesting that a Hummer and a SmartCar could drive the same distance, even though their tank capacity and mpg were completely different. It’s weird to think someone thought a hummer with those characteristics was a good idea."

"When a medium-mass main sequence star goes through 90% of its total existence and its hydrogen is exhausted. After exhausting the hydrogen the star will evolve rapidly into a giant star; however the giant star is the first step towards the star's death and only has 10% of its existence left."

"What I found interesting was that stars will resort to different elements when dying out."

"That a massive star will implode and explode on itself while it is dying."

"Pulsars are neutron stars that are rotating. I always thought they were resonating."

"Black holes and pulsars are always an interesting thing to talk about. The pulsar lighthouse model has always been fascinating to me because while we don't exactly know what a black hole is, we know that a pulsar is what it was just before (in most cases) and the pulsar we can actually see, which means we can study it. This is by far one of the most extreme objects in the universe, and I think it would be just so cool to see one in person."

"Black holes, everything about them is interesting and complicated."

"How black holes can't be seen."

"I found it interesting that you can't really see black holes."

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

"How a white dwarf is much larger than the two remnants of massive stars such as a neutron star or a black hole, but how can these two be much more massive than a white dwarf?"

"I found that medium-mass stars have a smaller life span than small mass stars confusing because I had previously thought that the bigger stars had longer lifespans."

"Why certain stars explode differently."

"Something that I found confusing was planetary nebulae. I am not really sure what it is or what it does."

"How a white dwarf can steal hydrogen from another star."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"The SmartCar gets better gas mileage but holds less gas while the Hummer holds more gas but gets less miles to the gallon."

"A Hummer H2 gets less than 10 miles a gallon, but can hold over 30 gallons of gas. A SmartCar ForTwo gets almost 40 miles a gallon but can only hold less than 9 gallons of gas. The balance of these two characteristics of each car makes the distance equal between them."

"The Hummer has a bigger gas tank but has a lower fuel efficiency. The SmartCar has a smaller gas tank but better fuel efficiency."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [73%]
Neutron star: massive main sequence star [54%]
White dwarf: medium-mass main-sequence star [62%]
(No stellar remnant observed yet): low-mass main-sequence star [54%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [77%]
Type Ia supernova: medium-mass main-sequence star [84%]
Nova: medium-mass main-sequence star [31%]
Low-mass main-sequence star: (no explosion possible) [69%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	* [1]
hours.	*** [3]
days.	** [2]
a year.	[0]
many years.	**** [4]
forever.	************** [14]
(Unsure/guessing/lost/help!)	** [2]

The first rule of astronomy class is...

"Do the reading assignments?"

"Ask questions?"

"Learn?"

"Stay focused?"

"Show up to class and pay attention?"

"Keep, quit, start?"

"Tuck in your pants?"

"Don't let your friend jump in a black hole?"

"I feel like I should know this or remember it but I really can't think of it..."

"Don't talk about astronomy class."

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

"What would happen if I took a basketball and threw it where a friend entered an event horizon? Would I see the basketball go through them? Distort their image?" (The basketball would "spaghettify" and stretch out into a long spiral of atoms that would slower and slower follow your friend's atoms as they approach closer and closer to the event horzion.)

"The space-time curvature is actually insane and I'm confused on the flatness discussed. Is everything on a plane?" (Not literally, but only in the sense of feeling the absence or presence of gravity.)

"I don't understand on how we can 'feel' black holes." (Even though light can't escape from a black hole, its gravity can be felt, even at respectively distance locations.)

"What do you recommend for staying motivated?"

"Do you love black holes?" (No, because black holes don't love you back.)

"How do we know how old the universe is?" (Because of the finite speed of light, we can use telescopes to actually see into the past--more on this after the second midterm.)

"What is the first rule of astronomy class?"

"What is the second rule of astronomy class?"

"Astronomy is cool."

Astronomy quiz archive: stellar evolution

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

Section 30674, version 1
Exam code: quiz06nG4s


Section 30674

0- 8.0 :
8.5-16.0 :	**** [low = 11.0]
16.5-24.0 :	***
24.5-32.0 :	******** [mean = 27.3 +/- 8.9]
32.5-40.0 :	******** [high = 40.0]

Section 30676, version 1
Exam code: quiz06s0ho


Section 30676

0- 8.0 :	**** [low = 7.5]
8.5-16.0 :	******
16.5-24.0 :	*********** [mean = 23.8 +/- 9.4]
24.5-32.0 :	***********
32.5-40.0 :	********** [high = 40.0]

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (SLO campus)

Astronomy 210, spring 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 evolution of medium-mass stars, massive stars, neutron stars and black holes.

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.

"You always use cool things to compare it to like using a car mpg/tank/range comparison to a main-sequence lifetime."

"Hummer/SmartCar anecdote. It really messed with my perspective."

"The Hummer vs. SmartCar analogy, because the car scenario makes sense and seems like it would transfer over to the stars, but it just doesn't. It gives me a new appreciation for the low-mass stars."

"We can't compare cars to stars. Stars are completely different and store energy different."

"That many smaller stars will outlive the sun."

"To discover that the bigger stars die faster than the smaller ones. This makes sense as the bigger stars have faster fusion rates which means that the run out of hydrogen faster. The smaller ones fuse at a slower rate and therefore take longer to die and this makes sense to me."

"I think it's amazing that not a single red dwarf star has died of old age anywhere in the universe! Thats how old they can be."

"That the larger the star the shorter the lifetime. I always would have thought the opposite for some reason."

"The death of stars--I think it's cool that the mass of the stars affects the way in which a star may die."

"To find out how stars die and about the white dwarfs and how they die alone. RIP."

"Nova explosions--it's hard to believe that something like that takes place in this universe!"

"The subject of star death. I have often heard people use the term 'supernova' before, but never really thought anything about it other than the fact that it was some form of explosion. So while I have always known what it really refers to on a very, very basic level. But really being able to see all the visuals and learn about the different types of star deaths was just really interesting to me personally. However, I am having a hard time pairing the right explosion with the stars they go with."

"The video link of the stacked ball drop. I had never seen nor heard of this. It was then easier to image the core implosion-explosion giving me a visual to see."

"Pulsars, because they're described as mysterious signals...cool."

"I found the mass difference of stars and black hole fascinating. The concept of black hole is so popular, yet so unknown."

"Reading about what black holes are and how they work."

"That black holes are not visible at all but you can still tell it's there."

"To learn about what would happen if you jumped into a black hole. I just thought this was cool because when I was a kid me and my friends would constantly talk about jumping in black holes like it was some joke and it was nice to learn, or at least get the idea of what would actually happen if you did that."

"'Spaghettification.' I've been anxious to learn a little more about black holes, so knowing that it would seem to be an infinite amount of time to an observer before something falling in circles and enters the event horizon is super interesting and scary to me."

"I found black holes quite interesting, specifically the way gravity works in black holes. The way space-time works and how the object going into the black hole looks to observers is very strange."

"Nothing really."

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

"How at the end of a medium-mass stars lifetime that it becomes a giant before it dies off. Wouldn't it just get smaller as it dies?"

"How a white dwarf can steal hydrogen from a neighboring star?"

"Novae were confusing. I don't really get how a white dwarf is able to siphon off the energy from another star."

"That stars actually die--they have a life, they live their life, and then they die?"

"Matching the end-of-life stage with the corresponding main-sequence star mass."

"Navigating the deaths/explosions of specific stars and could use in-class clarification."

"Having a hard time sorting through the information to compartmentalize each actual stage and pairing it with the star it goes with. "

"The process by which heavy elements are created."

"How a supergiant can implode-explode? I understand the concept of exploding but the idea of a star imploding first confuses me."

"When type II supernovae make heavier elements and ultimately explode, how do these heavier elements get all the way to us?"

"Density confuses me so much, so if you can explain it in class that would help a lot."

"How do they know exactly what happens in a black hole if everything is ultimately destroyed?"

"What black holes really do."

"Nothing was confusing to me, it was all pretty straightforward"

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.

"The Hummer can hold more gas, but uses it more quickly, so it evens out."

"A Hummer H2 and a SmartCar ForTwo can travel the same distance on a full tank of gas because of the differences in their fuel capacity and efficiency. The Hummer is an extremely inefficient car, but to compensate for that fact it is made with an extremely large gas tank capable of carrying a lot of fuel. The SmartCar is a much smaller car, and while it's many times more efficient than the Hummer, it has a proportionally appropriate much smaller gas tank. Because of the differences in how much fuel these cars use and how much they can carry, despite their major size difference, they both end up having the same range."

"The Hummer H2 contains a larger tank for the gas therefore is able to hold more gas, and SmartCar ForTwo has great mileage but the gas tank is significantly smaller therefore cannot hold much gas. so the two cars travel the same distance."

"The Hummer would need to make more pit stops to refuel?"

"They both have the same size gas tank?"

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)

Black hole: massive main sequence star [76%]
Neutron star: massive main sequence star [43%]
White dwarf: medium-mass main-sequence star [41%]
(No stellar remnant observed yet): low-mass main-sequence star [38%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)

Type II supernova: massive main sequence star: [73%]
Type Ia supernova: medium-mass main-sequence star [65%]
Nova: medium-mass main-sequence star [43%]
Low-mass main-sequence star: (no explosion possible) [54%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.

seconds.	***** [5]
hours.	** [2]
days.	[0]
a year.	[0]
many years.	*** [3]
forever.	************************* [25]
(Unsure/guessing/lost/help!)	** [2]

The first rule of astronomy class is...

"Bring snacks?"

"It's boring but important?"

"Shoot for the stars?"

"Always pay attention?"

"Show up?"

"Do the reading assignments?"

"Ask questions?"

"Look up?"

"Having fun learning about space and our universe?"

"To be informed of and to abide by all student policies, and to call you P-dog?"

"Do your work every week?"

"Try your hardest?"

"What P-dog says, goes?"

"I don't remember. Don't die?"

"Do not talk about astronomy class."

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

"Why isn't the carbon-oxygen core of a white dwarf not hot enough to convert the carbon and oxygen into heavier elements? (Even though the temperature is really hot, it doesn't have enough pressure/gravity to squeeze carbon together to fuse, unless more mass is added to it by another star.)

"Is it possible for another star to move close enough to our sun to cause mass transfer and accretion disks?" (It's too late for that, it should have been a star that was born nearby at the same time as our sun.)

"Why don't pulsars collapse in on themselves?" (They don't have quite enough mass and gravity to crush themselves into a zero-size black hole, but they did have enough mass and gravity to crush all their atoms and compact them into neutrons.)

"I know that in the in-class work we will have to fill in a stellar evolution chart, the topic is still feeling way over my head. I'm sure you will go into more detail about it before we do the assignment, but I just thought I'd put it out there."

"What were to happen to an object that we observe going into a black hole? Would we ever see it come out the other side or would the black hole appear to change?" (We won't ever be able to see what happens to the object after it enters the event horizon surrounding the black hole (as no light from inside the event horizon can escape). However, we would then wind up with a black hole that has slightly more mass and gravity.)

"What is our next quiz going to be on?" (This stuff--the birth, lives, and deaths of stars.)

"Is the final exam going to be cumulative? (Yes, but selectively cumulative, not "everything cumulative." You'll be given a definitive list of things on a study guide, and if something's not on that list, then it's not on the final exam.)

"Would you jump into a black hole to potentially live...F-O-R-E-V-E-R...rrrr?" (I don't think I'd enjoy the spaghettification process. Technically, you'd definitely die, it's just that no one would live long enough to be able to watch the process complete itself.)

"How was your spring break?" (Mrs. P-dog and I had an awesome time in the mountains. How about yours?)

"'sup?" (Chilling. You?)

"I plan on studying more."