which two characteristics are used to classify stars on the hertzsprung - russell diagram?\nsize and…

which two characteristics are used to classify stars on the hertzsprung - russell diagram?\nsize and density\ndensity and composition\ncomposition and temperature\ntemperature and absolute brightness
Answer
Brief Explanations:
The Hertzsprung - Russell (H - R) diagram plots stars based on their surface temperature (spectral type) on the horizontal axis and absolute brightness (luminosity) on the vertical axis.
Answer:
temperature and absolute brightness