Messier 92 (Hercules)
The globular cluster Messier 92 (NGC 6341) in the constellation Hercules
Fig. 1 - Very tightly packed, containing roughly 330,000 stars in total: The globular cluster Messier 92 in Hercules, photographed with an 8-inch f/5 Newtonian reflector on a ZWO AM5 mount.
| Object name: | Constellation: | Coordinates: | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| Messier 92 (NGC 6341) | Hercules | 17h17m / +43°08' | 14' | 6.4 mag |
Messier 92 (NGC 6341) is a globular cluster in the constellation Hercules. It is only slightly less bright than Messier 13, the most celebrated globular cluster in the northern sky, but appears about one third less extended. At the same time, Messier 92 is more centrally concentrated, making it a particularly rewarding target for larger telescopes.
Messier 92 is one of the most metal-poor globular clusters known. Its stars contain only trace amounts of elements heavier than hydrogen and helium, indicating that the cluster formed during the earliest epochs of the Milky Way. This primordial chemical composition is one of the reasons why Messier 92 is considered among the oldest stellar systems in our Galaxy.
Messier 92 lies about 26,700 light-years from the Solar System and was discovered by German astronomer Johann Elert Bode in 1777 before being independently rediscovered by Charles Messier in 1781 (source: Wikipedia).
Technical Details:
Exposure time: 2h 54min (58x3min)
Gain: 100
Temperature: -10°C
Date: June 18/19, 2025
Processing: Astro Pixel Processor (APP) and Photoshop
Calibration: Darks, flats, and bias
Equipment:
Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 8" f/5 "ONTC" Newtonian telescope, ZWO AM5 Strain Wave Mount, ZWO OAG-L off-axis system, ASI 174MM Mini guide camera, ASIAIR Plus
Messier 92 was also captured with a 16-inch dobsonian on an equatorial platform. The image can be seen here.
Fig. 2 - Search chart for Messier 92. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net.