Recap: Overview of Stellar Interiors

• non-relativistic vs relativistic
• non-degenerate vs degenerate

Degenerate Stars: White Dwarfs

• non-relativistic degenerate stars
• observed white dwarfs
• Sirius B: optical images here and here, zoom, X-ray (Chandra)
• white dwarfs in globular cluster M4 and NGC 6397
• relativistic degenerate stars
• Chandrasekhar limit
• white dwarf cooling sequence: Gaia HR diagram, more Gaia white dwarfs

Chandrasekhar Limit and Implications

• original paper: Chadrasekhar (1931)
• testing the limit: observed white dwarf mass distribution:
  • count histogram from Liebert+ (2005)
  • normalized distribution from Finley+ (1997)
  • density distribution from Kepler+ 2007
• preview of implications: core collapse and Type Ia supernovae