Light Curves

13.14 - Understand the light curves of the following variable stars:
a) short/long period
b) eclipsing binary
c) cepheid
d) novae and supernovae
13.15 - Understand the causes of variability in the light curve of eclipsing binary stars
13.16 - Understand how Cepheid variables can be used to determine distances
13.18 - Understand how the period of an eclipsing binary star can be deduced from its light curve

How bright a source of light is can be measured. A light curve is a graph that displays how bright an object is over a period of time.

We will look at light curves for the following star types:

- Variable Periodic
- Eclipsing Binaries
- Cepheids
- Nova / Supernova

All stars are to some extent 'variable'. They produce different amounts of heat and light at different times. Our Sun is unpredictable to some extent but fairly stable. We can be sure that it will produce the same amount of light and heat for the next few billion years. Not all stars are like our Sun. Here we look at some variable stars.

We can produce a chart showing the light curve of the variable star. This plots luminosity or brightness against the number of hours or days. We can then see what pattern the light curve produces. Extrasolar planets are frequently found by looking at the light curve of their Sun.

 

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