Week 4    go to         http://uofgts.com/Astro/week4.html

Stars, How do we know? Stellar Evolution,

Visualizing the Universe, one pixel at a time.

Stars How Do We Know what they are?

The Electromagnetic Spectrum

  • radiation
  • Cosmic Rays
  • Visible Light
  • Solar Spectrum
  • Stellar Spectrum

Classification of Stars

  • Spectral Type
  • Luminosity

The HR Diagram

  • Absolute Magnitude or Luminosity Vs Spectral Type/Temperature/Color

Evolution of a 1 solar mass star (Sun)

  • Nebula
  • T-Tauri
  • Main Sequence
  • Red Giant
  • Nova
  • White Dwarf (C-N-O)

Evolution of a 5 - 8 solar mass star

  • Carbon Star explodes (fusion stops at C-N-O)
  • No remnant

Evolution of a 8 - 80 solar mass star (Super Giant)

  • Shell detonation
  • blows off envelope
  • leaves collapsed core
  • Either a neutron star, or a Black Hole
  • Fe Fusion adsorbs energy
  • The Star collapses
  • Super Novas
  • Some heavy elements beyond Fe (Iron) Form during the Super Nova

End Points

  • White Dwarfs
  • Neutron Stars
  • Black Holes

Celestial Sign Posts in the Summer Sky

8 - 12 pm, in August

Summersky-south-anim