NGC 654 -- Open Cluster in Cassiopeia
Secret Deep 4
The Open Cluster NGC 654 is listed in O’Meara’s book “The Secret Deep” as object number
four. This Open Cluster was one of the five open clusters that I observed on December 16,
2017 that create a lop-sided-circle near the star Ruchbah (Delta Cassiopeiae). Although, the
clusters NGC 663 and M103 are much larger and more conspicuous, NGC 654 is the brightest
of the five open clusters in the loop. This is due in no small part because of HD 10494 a F-class
luminous supergiant which is the brightest star in the cluster. HD 10494 appears slightly yellow
to me and thus appears so in my drawing. There is dim reflection nebula (vdB 6) that is present
at the cluster but the soft glow that I saw was due to dim background stars that I could not make
out clearly and not the reflection nebula which remained invisible to me. An interesting fact about
NGC 654 as pointed out in Kanipe & Webb’s “Annals of Deep Sky Vol 4” is that several stars
have been ejected from this cluster and are racing away from it. At least one of these runaway
stars is currently in the constellation of Perseus and another in Andromeda. See the drawing of
NGC 663 to see how NGC 654 relates in size.