Question 1 Question 2 Question 3

Death of heavy stars

• What is left after a Type II supernova?
  • determined by mass
  • Star Wars trash compactor scene analogy
  • Stellar Evolution Summary
• neutron star
  • HST Image of a neutron star: 27 km across, 660,000 K temp.
  • Pulsar
    • Crab pulsar
    • lighthouse model
    • animation of lighthouse model
    • frequency of pulsar interpretted as sound
  • Recent gravitational waves announcement was about two colliding neutron stars
• Black Holes
  • Einstein's Theory of General Relativity: gravity warps space-time
  • Visualization of orbits with general relativity
  • Escape velocity revisited
  • Escape velocity for black hole

    object	Mass (kg)	radius (m)	escape velocity (m/s)
    Earth	6x1024	6.4x106	1.1x104
    Sun	2x1030	7x108	6.2x105
    Neutron Star	4x1030	2x104	1.6x108
    Black Hole	8x1030	(1)	3.3x1010

  • Schwarzschild radius
  • Artist rendering of black hole
  • Matter falling into black hole forms an accretion disk
  • Jets emitted from accretion disk
  • artist rendition of jets
  • Black holes can have binary partner
  • drawing of Cygnus X-1
  • side, back, front
  • Our galaxy has an estimated 100 billion stars and 100 million stellar remnant black holes.
  • Falling into a black hole - "spaghettification"
  • red shift
  • Picture of jets seen by radio telescope
  • time dilation
  • Explanation of time dilation
  • Supermassive black hole M87
    • HST picture of M87
    • Another view of M87 jet
    • M87 in radio
  • Center of our Milky Way galaxy
    • 7.5-8 kParsec away
    • in direction of constellation Sagittarius
    • size of black hole = 44 million km diameter (0.3 AU)
    • mass of black hole = 4.3 million solar masses
    • Composite picture (Hubble, Spitzer, Chandra), caption