Messier 15 (Pegasus)
Fig. 1 - Home to over 100,000 stars: The globular cluster Messier 15 in the constellation Pegasus, photographed with an 8-inch f/5 Newtonian reflector on a ZWO AM5 mount.
| Object name: | Constellation: | Coordinates: | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| Messier 15 (= (NGC 7078) | Pegasus | 21h30m / +12°10' | 18' | 6.2 mag |
The globular cluster Messier 15 (NGC 7078, "The Great Pegasus Cluster") in the constellation Pegasus. Messier 15 is one of the most densely packed globulars known in the Milky Way galaxy. Its core has undergone a contraction known as 'core collapse' and it features a dense central core, with an enormous number of stars clustered around what is likely a central black hole.
Home to over 100,000 stars, the cluster contains a large number of variable stars and pulsars. It also contains Pease 1, the first planetary nebula discovered within a globular cluster. Messier 15 is about 35,700 light-years from Earth, 175 light-years in diameter and was discovered by Italian-born astronomer Jean-Dominique Maraldi in 1746 (source: Wikipedia).
Exposure time: 4h 6min (82x3min) at gain 100 and -10°C, taken on September 20 / 21, 2025. Processing with Astro Pixel Processor (APP) and Photoshop. Darks, flats, and bias were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 8" f/5 "ONTC" Newtonian telescope riding on a ZWO AM5 Strain Wave Mount, ZWO OAG-L off axis system, ASI 174MM Mini guide camera, ASIAIR Plus.
Messier 15 was also captured with a 16-inch dobsonian on an equatorial platform. The image can be seen here.
Fig. 2 - Search chart for Messier 15. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net.