Binary Star Evolution
Binary stars exchange mass through Roche lobe overflow. The primary star expands, transferring material to its companion through the L1 point.
Detached Binary
Primary Star
Mass:5.0 M☉
Radius:4.2 R☉
Type:B Star
Secondary Star
Mass:2.0 M☉
Radius:1.8 R☉
Type:A Star
System
Period:5.2 days
Separation:20 R☉