Credit score: Douglas J. Struble
In case your observing web site is darkish and you’ve got entry to not less than a 14-inch telescope, do your self a favor and goal the Hercules Galaxy Cluster. Its primary official designation is Abell 2151, a member of a catalog of two,712 wealthy northern clusters of galaxies initially revealed by American astronomer George O. Abell. Later inclusions of southern clusters introduced the total to 4,073. A real deep-sky object, Abell 2151 lies 500 million light-years away.
One of many coolest features of this cluster is that almost half of its 200-plus members are spirals. And several other of these are interacting with different members of the cluster.
In case your scope has a go-to drive, goal the brightest member, elliptical galaxy NGC 6047. With out go-to, find the Fifth-magnitude star Kappa (κ) Herculis. Then transfer 1° northwest, and your discipline of view ought to seize a number of dozen seen galaxies.
A finder chart is a should if you wish to determine the faint patches of sunshine. Seven of the galaxies in Abell 2151 are brighter than 14th magnitude: NGC 6047 (magnitude 13.5), NGC 6061 (13.6), IC 1194A (13.6), NGC 6055 (13.7), IC 1185 (13.9), NGC 6045 (13.9), and NGC 6056 (13.9).
The one beginner astronomers take pleasure in viewing essentially the most is NGC 6045. For those who look fastidiously at its japanese tip, you’ll discover the magnitude 15.5 lenticular galaxy PGC 84720. To most observers, this combo appears like a hockey stick or the letter L, which can be regular, flipped, or reversed relying in your scope’s optics.
Along with a big telescope, to efficiently view this galaxy cluster you’ll want to make use of eyepieces that give magnifications of 250x and extra. Excessive powers will enhance the distinction between the galaxies and the background sky. Additionally keep in mind that the diameter of Abell 2151 is greater than 1°. So transfer your discipline of view round to see each galaxy seen.
