A35 Lectures 16-17 - Lecture 16 Planetary Nebula A low mass star(between.4 and 4 Msun sheds its outer layers undergoes bursts of luminosity and all that

A35 Lectures 16-17 - Lecture 16 Planetary Nebula A low mass...

This preview shows page 1 - 2 out of 2 pages.

Lecture 16: Planetary Nebula: A low mass star (between .4 and 4 M sun ) sheds its outer layers, undergoes bursts of luminosity, and all that remains is a fiercely hot exposed core called a planetary nebula . White Dwarf: The burned-out core of a low-mass star cools and contracts until it becomes a white dwarf. No more nuclear interactions will take place within it, and as the star cools, it dims. Oldest white dwarves have been cooling for 12 Gyr. Tycho’s SN of 1572: Tycho Brahe observed a supernova in 1572, and asserted the controversial idea that the galaxy was by no means unchanging. In the last stages of its life, a high-mass star has an iron-rich core surrounded by concentric shells. Thermonuclear reactions stop with iron because the forming elements heavier than iron require an input of energy rather than causing energy to be released. Synchrotron Emission: Particles near the speed of light in a magnetic field.
Image of page 1
Image of page 2

You've reached the end of your free preview.

Want to read both pages?

  • Spring '09
  • RobertKirshner
  • Tycho Brahe, Supernova, White dwarf

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes