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

Astronomy 210, spring semester 2014
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, and keep-quit-start mid-semester resolutions.

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 the comparison of the Hummer with the SmartCar was cool. I never thought about how they could go the same amount of range with the same tank. Crazy!"

The car range comparison, even though I still don't quite understand how it relates to the death of medium-mass stars."

"I find it interesting that when stars are dying they start to fuse heavier elements. And that's why those elements exist in our universe."

"What was interesting for me was looking at how a medium mass goes from being 'alive', eating through all its supply (like eating everything in your fridge), turning into a white dwarf and then finally exploding."

"It was interesting to learn that low mass stars take so long to die and especially that none have even died yet and that some are older than our galaxy."

"I thought learning about black holes was really interesting. That was something I was interested to learn about in the beginning of this class. The most interesting thing to me about black holes is that you can be falling in them forever. And the part about the event horizon and how once you get to that you're screwed, you can't get away. It's also crazy that we can't see them but we still have proof some how that they are still there."

"I liked the way that when medium-mass stars start to die they just steal from the star closest to them. I do feel bad for the star next to it though--it has no say in the matter."

"It was super interesting to read that basically one day the atoms that make us up are going to be in the nebula surrounding the sun when it dies in 5 billion years. I have never thought about life like that and it makes me feel better about dying one day because my atoms will be always be a part of the universe, even long after my body is decomposed."

"After going through the reading and the online presentation previews I found the topic of expansion cooling interesting. I found this topic interesting due to how the outer layers of the star expand and cool."

"I personally found it interesting when they were talking about the white dwarf star. And how they don't consider calling it a star, since it contains no gas. How they think it should really be called 'compact object.'"

"I think it was really interesting that a low mass star will last longer than a star with a larger mass. As well, that massive stars can become a black hole or a neuron star."

"Degenerate matter--how white dwarf stars are supported by it, it is super interesting and just epic."

"The expansion of medium mass stars into nebulae."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"How black holes can be difficult to discuss with others due to either believing or not believing that they truly exist."

"I don't understand the difference between all the types of explosions."

"I thought mainly the black holes were confusing because how can you say something is there when you can't even see it or we haven't even really found one. I know in theory we can prove they're there because we can see their effects, but how?"

"The most confusing thing for me was about the life and death of a star and the different kinds of stars and how they run out of stuff to 'eat' and convert differently. I am very confused about that and how to remember it and just what it means in the first place."

"How does one actually know what it's like to step into a black hole."

"It took me a while to understand how massive stars die. But once I understood it more I actually found it very interesting as well."

"I don't understand black holes. how do we see them, how do they work?"

"I'm kind of confused with the stars' mass and how they die because it was a lot to read and keep track of."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.
"A SmartCar has a smaller engine but is more fuel efficient while a Hummer has a large engine but burns it up rapidly."

"The SmartCar has a better gas mileage but a smaller tank whereas the Hummer has a bigger tank but worse gas mileage."

"Because of the gravity."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)
Black hole: massive main sequence star [82%]
Neutron star: massive main sequence star [55%]
White dwarf: medium-mass main-sequence star [74%]
(No stellar remnant observed yet: low-mass main-sequence star [53%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)
Type II supernova: massive main sequence star: [95%]
Type Ia supernova: medium-mass main-sequence star [89%]
Nova: medium-mass main-sequence star [55%]
Low-mass main-sequence star: (no explosion possible) [68%]

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.  * [1]
days.  [0]
a year.  [0]
many years.  *** [3]
forever.  ************************* [25]
(Unsure/guessing/lost/help!)  **** [4]

The first rule of astronomy class is...
"...respect P-Dog?"

"...go to class?"

"...pretend like you're a professional astronomer--which would call for reading and doing homework."

"...quit procrastinating and start work sooner."

"...to answer all of the questions!

"...don't take P-dog's chillaxness for granted."

"...respect the goatee."

"...all hail the mighty gods of space."

"...don't waste food, that's not good science."

"...all of the tools are given to you, it's up to you to use them and succeed in this class."

"...you don't talk about astronomy class."

"...not show up late to the totally real house party."

"...what happens in astronomy class, stays in astronomy class."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Did you hear about the photo taken on Mars from NASA's Curiosity rover? It's a picture of the landscape on Mars and there's this unexplained light that people are speculating points to alien life." (...or periodic glitches from cosmic ray radiation, or shiny rocks. They see something like this about once a week.)

"Is it true that the Stephen Hawking has recently released statement saying that black holes don't exist?" (Actually his latest proposal is that our understanding of event horizons should be revised slightly with better quantum mechanical theories. Other physicists have different opinions on this.)

"Where does one buy that AstroBlaster toy?" (Amazon.com has them.)

"Have you considered possibly either going over the in-class activities before we turn them in or posting a 'key' online after class? A lot of us agree this would be helpful." (If you are uncertain of your answers even after checking with other groups, then make an effort to ask me questions to clarify these for you, either during the wrap-up whole-class discussion or after class ends (which I strive to finish at least slightly early so you can have time for this.)

"When I walk into your class my head always sings, Lady Gaga's 'Venus': 'take me to your planet, take me to your planet...'"

"Do you have any pets? Like that cat in the picture?" (Pocahontas has her own Facebook page. She posts about her housemates as well.)

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