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

Astronomy 210, fall semester 2016
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 SmartCar versus Hummer H2 example. I never thought about that in that way."

"'Core-starvation'--it reminds me of how I used to live."

"The different types of supernovae--I didn't realize there was a correlation between mass and type of supernovae."

"The way white dwarfs steal hydrogen from accompanying stars."

"Supernovas are so interesting. Its amazing how are solar system can produce something like this. results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times to no more than 40–50 times the mass of the sun (M) to undergo this type of explosion."

"The idea that stars live and die. I never thought a star would die."

"How no low mass star has died yet. That is crazy."

"Everything is interesting, but confusing at the same time."

"I loved the way you present the videos and slides but, particularly the black hole presentation."

"That stars can turn in to black holes is pretty cool."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The big versus small car analogy."

"Trying to remember all of the different stages."

"Which explosion happens to which star confused me the most. Maybe I just need it to be explained to me by someone else."

"Still slightly confused on the the life span of main sequence stars and their end-of-life stages."

"End stages of a main-sequence star and the types of explosions associated."

"I got confused about star explosion types at first."

"Black holes."

"The idea of black holes was confusing to me, mainly the spaghettification."

"Most of it was pretty confusing, honestly."

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 has a larger tank but less mpg while the smartcar has a smaller tank of gas but much more mpg so they even out."

"The Hummer H2 has a larger tank of gas than the SmartCar. So even though the smartcar has better mileage the extra gas in the the tank of the Hummer makes up for the difference."

"Since the smart car is much smaller and lighter it needs a lot less gas than the huge armored Hummer that has to have a lot more fuel to go that distance."

"I had trouble with this analogy."

"This is possible because they are traveling the same distances."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)
Black hole: massive main sequence star [61%]
Neutron star: massive main sequence star [26%]
White dwarf: medium-mass main-sequence star [39%]
(No stellar remnant observed yet: low-mass main-sequence star [52%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)
Type II supernova: massive main sequence star: [65%]
Type Ia supernova: medium-mass main-sequence star [57%]
Nova: medium-mass main-sequence star [30%]
Low-mass main-sequence star: (no explosion possible) [49%]

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.  ******* [7]
hours.  *** [3]
days.  [0]
a year.  [0]
many years.  *** [3]
forever.  ********** [10]
(Unsure/guessing/lost/help!)  [0]

The first rule of astronomy class is...
"Never attempt to create a black hole in class."

"Pay attention."

"Re-read the chapters."

"Be a star?"

"Do your homework."

"Have too much fun, and show respect."


"Eat miso soup and go to house parties."

"Refer to your instructor as 'P-dog' and go to class!!!!"

"Try to succeed."

"Don't talk about astronomy class."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I hope to see a dying star in the sky in my lifetime."

"Could Michael Phelps swim out of the event horizon? Could someone be pulled out of it?" (Michael Phelps could get closer to the event horizon than any of us ever could, and still swim out. But he would not be able to swim out of the even horizon if he got inside--nothing could, even traveling at the speed of light.) 
"Why do we have too much reading this section?:)" (But it's good stuff.)

"Can you visually tell the difference between a supernova remnant and a planetary nebula?" (Yes, a black hole or a neutron star is at the center of a supernova remnant, and a white dwarf is at the center of a planetary nebula.)

"Please explain blackholes and supernova."

"Have a nice day."

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