NGC 6229: A Very Distant Globular Cluster

The globular cluster NGC 6229 lies in the Hercules constellation, which is best viewed in summer. Compared to the brilliant Messier 13 globular nearby, NGC 6229 is a dim 9th-magnitude object.

One cannot blame NGC 6229 for its faint appearance as it lives nearly 100,000 light-years away in the far outer reaches of the Milky Way. When William Herschel spied this globular on May 12, 1787, he took it to be a planetary nebula. It wouldn’t be until the 19th century that astronomers resolved the fuzzy “nebula” as an actual cluster.¹

My Observations

Due to the dim magnitude of this cluster, I’m struggling to find this dim cluster. I just changed out my 12mm for the 24mm eyepiece in case my navigation is off. I’ve been slewing back and forth and now notice (after much staring) a pinpoint fuzzy dot. Now, as I switch out to the 12mm eyepiece, I’m able to make out a fuzzy small circle that truly resembles a planetary nebula at first. As I use peripheral vision, the faint light ever so slowly grows. Two equally brighter stars are beneath the cluster and make an almost perfect triangle centered in the eyepiece.

Key Stats

Constellation	Hercules
Best Viewing	Summer
Visual Magnitude	+9.3
Absolute Magnitude	-8.0
Distance from Earth	100,000 ly
Diameter	130 ly
Apparent Size	4.5 arcmin
Milky Way Location	Outer Halo
My Viewing Grade	C+

Sources and Notes

The NGC 6229 banner photo is based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

¹ Frommert, Hartmut. NGC 6229, http://spider.seds.org/spider/MWGC/n6229.html.