Data

When reading the Hertzsprung-Russell Diagram (HRD), it is important to remember that you have two important pieces of data to use when classifying your star. You need to have a value to read each axis of the graph.
As you have already learned, we use two units for the classification; one is for luminosity, measured in solar units and the other is for temperature, measured in kelvin. You must have one piece of data for each of those units and read the graph based on it.

In the table below, the data for temperature is circled with blue and data for luminosity is circled with red .