Stars

Star classification

  • color

  • temp.

  • size

  • chem. comp.

  • luminosity

  • brightness


Life cycle of a star

  • Low-mass star: red supergiant —> supernova —> black hole/neutron star

  • High-mass star: red giant —> plantary nebula —> white dwarf —> black dwarf


Hertz-Sprung Russel Diagram

  • used to classify stars

  • main sequence holds 90% of stars

  • y-axis: brightness/luminosity

  • x-axis: temperature


  • nebulae: huge clouds of gas & dust made by stars

  • nuclear fusion: process which powers a star, occurs in center of nebulae

  • stellar ignition: when a star is first powered

    • when it does not occur, creates a brown dwarf (too big to be planet, to dim to be star)

  • protostars: “stars” that cannot yet turn hydrogen to helium