Light Curve And Photometry Flashcards
What is the light curve?
The brightness of a supernova as a function of time.
What do the properties of the light curve depend on? (3)
- Kinetic energy produced in the supernova explosion itself.
- The amount of 56Ni produced in the explosion (depends on energy of explosion).
- The mass and radius of the progenitor star.
- The chemical composition of the ejecta.
What is extinction?
Light appears less bright as it passes through dust.
Why does extinction lead to reddening?
Dust does not extinguish light equally at all wavelengths. In general, light of bluer wavelengths is preferentially extinguished.
What is the light curve dominated by?
Light curve is dominated by energy put into the ejecta from the decay of radioactive elements produced in the explosion.
What does the shape of the light curve depend on?
How easy it is for energy to escape at any given time.
What does the rate at which energy escapes at early times, when the ejecta are still dense and opaque, depend on?
The mass of the ejecta.
How fast the ejecta is expanding.
What effect does the decay of radioactive elements produced through nucleosynthesis have?
The decay of these elements heats the ejecta. The energy has to escape and so contributed to the light curve.
What is Phillips relation?
Relates the width of the light curve to the absolute magnitude (B-band) at maximum light. Small (delta m 15 B) = Broad light curve. Large = narrow light curve.
