| 5.17|| Perseus|
| 11 Persei, 14 Persei, 17 Persei, 56 Persei|9 Persei Wikipedia
9 Persei is a pulsating variable star in the constellation Perseus. Its apparent magnitude is 5.17. Located around 1,000 parsecs (3,300 ly) distant, it is a blue supergiant of spectral type A2Ia, a massive star that has used up its core hydrogen and is now fusing heavier elements.
It has one companion, B, at separation 12.3" and magnitude 12.0.