Since type Ia supernovae have a known brightness they can be used as standard candles to determine the distance to a galaxy.  In this section, you will be given a series of images for a few galaxies with supernova explosions.  Using the series of images, make a light curve of each of the supernova explosions.  Using the light curves, determine which supernova is of type Ia, and determine the apparent magnitude of the supernova at its peak brightness.  Using this, determine the distance to the host galaxy using an absolute magnitude of -19.3 which is the derived absolute magnitude for type Ia supernova.

  • After comparing the light curves of the supernovae with type Ia and type II templates, which supernovae were type Ia and which were type II?
     
  • How far away is the galaxy containing they type Ia supernova in parsecs?
     
  • If a type Ia supernova exploded in the Large Magellanic Cloud, what would the apparent brightness be when seen from Earth?
     
  • How close would the supernova have to occur to have the same apparent magnitude as the Sun when seen from Earth?

 

lightcurves

 

epn figure

Though Type II supernovae can vary significantly in brightness, all type Ia supernovae have approximately the same absolute magnitude.  This is due to the process in which they supernovae occurs.  Type Ia supernovae occur when a white dwarf accumulates too much mass to resist the force of gravity.  This always occurs when the mass of the star reaches the Chandrasekhar Limit of 1.4 solar masses.