The line He I 4026 is weaker relative to K than in class B8. He I 4471 is considerably fainter than Mg II 4481.
|Lyr......||B9 III||18:55||+32 33||3.3||A0p|
|a Peg......||B9 V||22:59||+14 40||2.6||A0|
The luminosity classification is based on the appearance of the wings of the H lines.
|High resolution image|