Why are stars called main sequence?

1 Answer
Dec 19, 2015

They follow the trend line on the Hertz-Russell Diagram.

Explanation:

https://www.wwu.edu/depts/skywise/a101_hrdiagram.html

These are Hertzsprung-Russell Diagrams (HR Diagrams). The HR Diagram plots a star's luminosity (how bright it is) against how hot its surface is, using the sun as a base for luminosity.

The diagram below plots some well know stars on the sequence.
http://oneminuteastronomer.com/808/hr-diagram/
Most stars follow the main sequence, with bright stars being hot and cool stars being dim. There are a few exceptions, however, the most notable being White Dwarfs, Giants, and Supergiants.

Read more about the HR Diagram here , here, and here.

Read more about the Main Sequence here and here.

Read more about stars in general here.