NGC 6910 -- Open Cluster in Cygnus
The Rocking Horse Cluster
On the evening of October 12, 2018, I only had a couple of hours of clear sky before the
clouds moved in bringing the rain. Not knowing exactly how much time I had, I opted to
bring out my travel scope instead of spending time setting up a larger scope. I decided
on just one object for the evening, the Rocking Horse Cluster. NGC 6910 is a small but
attractive little open cluster less than one degree from Sadr (The Swan’s Breast) which also
marks the center of the Northern Cross. Easily located under low power it is best enjoyed by
increasing the magnification so that the bright star Sadr is out of the field of view.
Nestled between a triangle of brighter stars a stream of dimmer stars waves through the
triangle, providing a pleasant view. Stephen O’Meara, “The Secret Deep”, suggests the
name of the cluster should be the Inchworm Cluster, but I personally prefer the name
suggested by Peter Birren, “Objects in the Heavens”, of the Rocking Horse Cluster. Both
names reflect on the wave of stars as they move through the triangle and either name fits the
little cluster well.
Many amateur astronomers have seen this little cluster since it is one of the Herschel 400
observing objects, but I worry that they might not have spent enough time with it to really
bring out its charm in the eyepiece. It is a worth a second view and remember to up the
magnification to eliminate the glare of Sadr.
clouds moved in bringing the rain. Not knowing exactly how much time I had, I opted to
bring out my travel scope instead of spending time setting up a larger scope. I decided
on just one object for the evening, the Rocking Horse Cluster. NGC 6910 is a small but
attractive little open cluster less than one degree from Sadr (The Swan’s Breast) which also
marks the center of the Northern Cross. Easily located under low power it is best enjoyed by
increasing the magnification so that the bright star Sadr is out of the field of view.
Nestled between a triangle of brighter stars a stream of dimmer stars waves through the
triangle, providing a pleasant view. Stephen O’Meara, “The Secret Deep”, suggests the
name of the cluster should be the Inchworm Cluster, but I personally prefer the name
suggested by Peter Birren, “Objects in the Heavens”, of the Rocking Horse Cluster. Both
names reflect on the wave of stars as they move through the triangle and either name fits the
little cluster well.
Many amateur astronomers have seen this little cluster since it is one of the Herschel 400
observing objects, but I worry that they might not have spent enough time with it to really
bring out its charm in the eyepiece. It is a worth a second view and remember to up the
magnification to eliminate the glare of Sadr.