Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (NC 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.
"How elements are manufactured in stellar explosions is pretty awesome. My body is composed, literally of star dust, which is pretty amazing."

"How stars in close-binary systems can "steal" hydrogen. What dirty little thieves!"

"Neutron stars--they're so small, just 10 km, and still put out high amounts of heat and their increased spin rate. It's pretty cool that we even know they exist considering how small they are."

"Black holes have always fascinated me and no one has ever been able to explain them to me, and so now I have a better grip on them and still think they are awesome."

Black holes are interesting because you can't 'see' them, but you can 'feel' them."

"I found it interesting that small stars--red dwarfs--have never died (yet)."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"How neutron stars produce 'synchrotron radiation' beams. The book gives a brief description, but I could use some more clarification."BR>
"Why can a massive mass star become either a neutron star or a black hole? What causes one of the other? I didn't follow that too well."

"How does a star lose mass to another star?"

"There are a lot of different explosions to remember."

"Black holes are confusing--naturally."

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 cars can travel the same distance due to the differences in tank size. The smart car may get better gas mileage, but it can only hold so much fuel. Where as the H2 receives less than desirable gas mileage, but compensates by having a larger tank (more fuel)."

"The SmartCar has a much smaller gas tank?"

"The Hummer has way more fuel capacity despite its low mpg."

"I don't understand the comparison of stars and cars."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)
Black hole: massive main sequence star [79%]
Neutron star: massive main sequence star [54%]
White dwarf: medium-mass main-sequence star [64%]
(No stellar remnant observed yet: low-mass main-sequence star [57%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)
Type II supernova: massive main sequence star: [82%]
Type Ia supernova: medium-mass main-sequence star [64%]
Nova: medium-mass main-sequence star [54%]
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.  ******* [7]
hours.  [0]
days.  * [1]
a year.  [0]
many years.  *** [3]
forever.  *************** [15]
(Unsure/guessing/lost/help!)  ** [2]

The first rule of astronomy class is...
"...ask questions."


"...listen and read."

"...to call you P-dog?

"...don't forget your starwheel."

"...always donate to charity funnels?"

"...quit procrastinating."

"...to show up to class."

"...look to the skies and never stop questioning possibilities, and searching for answers to the unknown."

"...if stars didn't die, we would not exist."
"...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 time change messed me up, yo."

"Do you like country music?" (Funny that you should ask--I'm the faculty advisor for the Cuesta College Country Line Dancing Club. There are free lessons for students on SLO campus every Friday.)

"Has the death of a star ever been observed through a telescope and photographed or filmed? would this even be possible? (Happens somewhere about once or twice a year, captured through telescopes, or even with the naked eye.)

"Do you prefer teaching in SLO or Paso Robles?" (I love all my astronomy classes. Some, more than others...)

"Why don't stars feed off each other unless they're dying?" (When they begin to die and become either a supergiant or a giant, their outer layers have expanded outwards so much that they are now easier to peel off by a neighboring star.)

"Did you dress up for Halloween?" (Mrs. P-dog and I were the Cheshire Cat and the Dormouse from "Alice in Wonderland" at this year's Madonnaween.)

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