Astronomer's Toolbox

White Dwarfs

Try this!

Using the H-R diagram below, compare the following properties of a white dwarf to those of a main sequence star such as our Sun. You must choose one value for each question.

An H-R Diagram, also know as the Hertzsprung-Russell diagram, is of great importance in the study of stellar evolution. It is a two-dimensional graph that demonstrates the correlation between the spectral type, temperature and luminosity of stars. It shows that 90% of stars lie along a diagonal band known as the main sequence. Remaining stars also form their own individual bands in different spectral type areas of the graph.

1. Would a white dwarf have a larger or smaller proportion of hydrogen then a main sequence star?
   
   smaller larger

2. Would a white dwarf be larger or smaller in size than main sequence stars?
   
   smaller larger

3. Would the density of a white dwarf be lower or higher than a main sequence star?
   
   lower higher

4. Would the luminosity of a white dwarf be lower or higher than a main sequence star of the same temperature?
   
   lower higher

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This activity was developed by Jacqueline Slay, Largo High School, Largo, MD