STELLAR CHARACTERISTICS
 
      NAME
            Bright Stars → Proper Names ; Simbad Database
 
 
      DISTANCE
            Trigonometric Parallax ; Parallactic Angle Simulator
            Distance (parsecs) = 1 / Parallactic angle (seconds of arc); so 1 Parsec = 206265 AU = 3.26 light-years
            Stars are very far away ; Nearest Stars and the Stairway to Heaven
                    Gaia → 50 kPc   Andromeda Galaxy. We will need indirect methods go farther out
 
 
      BRIGHTNESS
            Apparent Brightness → Apparent Magnitude m (Hipparchus)   m v. intensity   decibels for sound   Richter Scale for earthquakes
            Absolute Brightness → Absolute Magnitude M, or Luminosity L
                    M = m if distance = 10 parsecs
                    m - M = distance modulus
 
                    Luminosity = Area × σ T^4 ; 1 Solar Luminosity = 4×10^26 watts ; [Limerick = two 1.2×10^9 watt reactors]
 
                            Absolute Magnitude or Luminosity ↔ Apparent Magnitude ↔ Distance
 
 
      TEMPERATURE
            from Continuous Thermal Spectrum ; Simulator
 
                            Temperature ↔ Color
 
            from Absorption Line Spectrum ; Fraunhofer Lines     Simulator
            Gallery of Stellar Spectra A B C ... O → O B A F G K M
 
                            Temperature ↔ Color ↔ Spectral Class
 
 
      CHEMICAL COMPOSITION
            from Absorption Line Spectrum ; stars are mostly Hydrogen and Helium, like the Sun
 
 
      RADIUS
            Stars are very far away, except for the Sun ; in the Visible and in the UV
            Luminosity = 4πR^2 × σ T^4
 
                            Luminosity ↔ Radius ↔ Temperature
 
 
------------------------------- THE HERTZSPRUNG RUSSELL RELATIONSHIP -------------------------------

 
      H. N. Russell's Diagram from 1910     Modern Diagram
 
      MASS
            Newton's version of Kepler's Harmonic Law: (M1 + M2)*P^2 = constant*(a1 + a2)^3
            Center of Mass: M1*a1 = M2*a2
               Visual Binary Stars    Sirius
               Eclipsing Binary Stars
               Spectroscopic Binary Stars
                   EROS1044
 
            MASS-LUMINOSITY Relationship; Luminosity ~ Mass^4
 
                            Mass ↔ Luminosity
 
      LIFETIME
            Lifetime = Fuel / Rate of fuel loss
            Lifetime = Mass / Luminosity ;
               Mass of Sun = 2×10^30 kg ; Luminosity = 4×10^26 watts
 
                            Mass ↔ Luminosity ↔ Lifetime
 
 
      SOURCE OF ENERGY
            Oxydation ; for TNT, 4×10^6 J/kg → thousands of years
            Gravitational Collapse ; Energy = G×M^2 / R = 10^41 J → millions of years
            Fusion ; Hydrogen to Helium   E = mc^2
               Curve of Binding Energy ; Fission v. Fusion ; Iron Peak
                   Proton-Proton Cycle ; E = mass lost × c^2 → billions of years

                 4 Protons = 6.692 x 10^-27

                 1 Helium4 = 6.647 x 10^-27

                             --------------

                             0.045 x 10^-27 kg x c^2 = 4.05 x 10^-12 J/He4

 
STELLAR EVOLUTION
 
      MATTER
            Stellar Matter
 
      TIME
            Star Formation
 
 
INTERSTELLAR MEDIUM
 
      HERSCHEL
            Observatory   Star Counts   Milky Way & Southern Cross
 
      INTERSTELLAR GAS & DUST
            Pleiades   Orion   Horsehead Nebula   Orion Complex
            Constituents = Hydrogen, Helium, all elements in absorption, Carbon Molecules, Complex Molecules
 
 
STELLAR BIRTH
 
      OBSERVATIONS
            Stars & Planets   Tour of the Orion Complex   Large Magellanic Cloud   N11   HH 47 and the Jet   Eagle Nebula
 
      PREDICTIONS
            Star Formation
 
      CONFIRMATION
            HH 30 Jets   HL Tauri   Dynamical Simulation
 
      A STAR IS BORN
            HR   In Balance   Stellar Clusters Age   Distance   Simulator
 
STELLAR EVOLUTION
 
      STARS LIKE THE SUN
            HR   Sun's Interior Temperature   Density   Triple-Alpha Fusion