![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Alpha_Persei_Cluster.png/640px-Alpha_Persei_Cluster.png&w=640&q=50)
Alpha Persei Cluster
open cluster in the constellation Perseus / From Wikipedia, the free encyclopedia
The Alpha Persei Cluster (also known as Melotte 20 or Collinder 39) is an open cluster in the constellation of Perseus.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Alpha_Persei_Cluster.png/640px-Alpha_Persei_Cluster.png)
To the naked eye, the cluster has several blue spectral type B type stars. The most luminous member is the ~2nd magnitude white-yellow supergiant Mirfak, also known as Alpha Persei. Bright members also include Delta, Sigma, Psi, 29, 30, 34 and 48 Persei. The Hipparcos satellite and infrared color-magnitude diagram fitting show the cluster as about ~172 parsecs away from us.[1][2]
Since the distance by the independent analyses agree, the cluster is an important rung on the cosmic distance ladder. The age of this cluster is about 50ā70 million years.[3][4]