Supernovae as Standard Candles

• What is a standard candle in astronomy?

  An object of known brightness
• Why can Type 1a supernovae be used as standard candles?

  They reach the same peak absolute magnitude
• What type of star system does a Type 1a supernova involve?

  An exploding white dwarf in a binary system
• What happens to the white dwarf in a Type 1a supernova?

  It increases in mass by attracting material
• What is the critical mass for a Type 1a supernova called?

  The Chandrasekhar Limit
• Why does the Chandrasekhar Limit lead to consistent explosions?

  It ensures the explosion is the same each time
• What characteristic shape does the light curve of a Type 1a supernova have?

  It always has the same characteristic shape
• What is an advantage of using Type 1a supernovae as standard candles?

  They are extremely bright
• How can Type 1a supernovae be used in astronomy?

  To measure distances to distant galaxies
• What is the absolute magnitude of a Type 1a supernova at its peak?

  About −19

  
• What are the steps to calculate the distance using a Type 1a supernova?

  1. Identify apparent and absolute magnitudes.
  2. Use the magnitude equation: m − M = 5 log(d/10).
  3. Substitute values and rearrange.
  4. Take logs to find distance.
  5. Calculate distance using \(d = 10 \times 10^6\) pc.