Hertzsprung–Russell
Ejnar Hertzsprung in 1911 and Henry Norris Russell in 1913 mapped absolute magnitude of stars against their colour.
Our Sun "Sol" is along a region called the Main Sequence.
The Bluer the Start is the hotter.
Ejnar Hertzsprung in 1911 and Henry Norris Russell in 1913 mapped absolute magnitude of stars against their colour.
Our Sun "Sol" is along a region called the Main Sequence.
The Bluer the Start is the hotter.