More exam 2 practice questions

When you answer these questions, even if we don't explicitly
ask, you should say (and answer) HOW DO WE KNOW THIS and
WHY is this answer plausible and consistent with what we know...




1) Why are core-collapse supernovae not found in elliptical
galaxies? (what's different about the star formation histories
of elliptical galaxies versus spiral galaxies like the Milky Way?)

2) Why are Type Ia supernovae found in both elliptical and spiral
galaxies?

3) What model of a Type Ia supernova explains the lack of hydrogen
in the spectra and explains question 2 above?

4) Why would you expect that core-collapse supernovae would
have a large range in intrinsic brightness?

5) Given question 3 above, why is it not surprising that
Type Ia supernovae are pretty similar in intrinsic brightness?

6) How do core-collapse supernovae and Type Ia supernovae make light?
What does radioactivity have to do with this?

7) Why are supernovae useful as distance indicators on gigantic
size scales? What is the amazing new result (which, by the way,
we'll talk about again in more detail later in the class) that
was uncovered in 1998 by studying Type Ia supernovae to
learn the size and fate of the universe?

8) READ JOCELYN BELL'S RECOLLECTIONS (in figures directory,
under Halloween)

9) If you were an extrterrestrial civilization, why might you
send signals similar to those that come from pulsars?

10) Why can't a pulsar be a spinning white dwarf?

11) When Nature makes a neutron star, why does it spin fast?
Why does it have a strong magnetic field?

12) Why does the lighthouse model of neutron star light emission
make pulsed light as seen from earth?

13) Where does the energy come from in question 12?
If your answer is correct, it has consequences for the neutron
star... what are they?

14) Which kind of supernovae leave behind a neutron star? WHY?