20141105

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

Astronomy 210, fall 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.

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.
"That a massive star can form a black hole or a neutron star."

"Black holes, one of the things I was most excited to learn about in this class."

"While eating cereal and reading the living alone analogy I almost spit out my beloved Frosted Flakes®!"

"All the metaphors and similes used to describe how stars work."

"Supernova expulsions are dope."

"Comparing a black hole to the main outlet for water in Lake Berryessa to pass through the Monticello Dam. Helps really get a visual to how you feel its presence and where 'the point of no return' is."

"The dying alone stars were really interesting because after the end of the main sequence lifetime they have no more hydrogen to eat so they slowly start to die off."

"Nothing, really."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Time dilation! It just doesn't make sense."

"Separating all of the different types of novae, supernovae, Ia supernovae, etc."

"Black holes."

"Literally everything...I'm lost!"

"The AstroBlaster™ toy example. I just don't understand what it's trying to show."

"Pulsars and black holes made no sense to me. I don't even know what a pulsar is or what it does. I understood what a black hole is, but the chapter made the rest of the information about it very confusing."

"Confused on the meaning of life."

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 Hummer has a large tank for gas but wastes gas faster, while a SmartCar has better gas mileage but a smaller tank!"

"Does it have to do with hydrogen? I honestly have no idea."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)
Black hole: massive main sequence star [62%]
Neutron star: massive main sequence star [46%]
White dwarf: medium-mass main-sequence star [65%]
(No stellar remnant observed yet: low-mass main-sequence star [49%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)
Type II supernova: massive main sequence star: [89%]
Type Ia supernova: medium-mass main-sequence star [78%]
Nova: medium-mass main-sequence star [51%]
Low-mass main-sequence star: (no explosion possible) [65%]

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.  ** [2]
days.  * [1]
a year.  ** [2]
many years.  ***** [5]
forever.  ********************** [22]
(Unsure/guessing/lost/help!)  ** [2]

The first rule of astronomy class is...
"...get ready to learn a lot."

"...go to class"

"have fun with it!"

"...jumping jacks

"...stay away from black holes."

"...a house party!"

"...question everything P-dog says."

"...call you P-dog?"

"...put in the effort."

"...gravity always wins."

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

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"The event horizon blows my mind, man. You'd fall inwards for two months but to everyone else it's forever? That's wild. Does that mean time travel is possible? Would you age two months or would it be forever because the view from your friends sees you continuing to keep inching down?" (Your remains would think it crossed the event horizon in two months, but your "friends" would watch you spiral in ever closer and slower towards the event horizon. I guess it is kind of like time travel, but in a one-way, time-stretching sense.)

"Could I crawl in your brain for a day and see how all of this makes sense for you?" (Get...out...of...my...head.)

"Can you go over the exploding and end of life stages of stars? Spend more time lecturing in the future because that is far more helpful and instructive!" (Yes, looking at some of your responses, that will be necessary.)

"Please go over novae and the different types of supernovae. Also some discussion on the black hole would be super neat!" (Super yes.)

"I've really enjoyed this class. I love space and I'm thankful that I'm starting to understand how the universe works!" (You're welcome.)

"I really like the way you make the presentations interesting by writing them in the 'P-dog' way! I remember what I read far more from your presentation than I do with the boring 'educated' book writers."

"Not really sure what the first rule of astronomy class is..."

"Do you believe time is finite?" (I don't know. But this semester is.)

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