| 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) in the constellation Pegasus. Messier 15 is 33,600 light-years from Earth, 175 light-years in diameter and was discovered by Jean-Dominique Maraldi in 1746. It is one of the most densely packed globular clusters known. With an age of 12.5 billion years, it is also one of the oldest known globular clusters in the Milky Way galaxy. Messier 15 contains Pease 1, the first planetary nebula discovered within a globular cluster. It was named after American astronomer Francis G. Pease, who detected it in 1928 (source: Wikipedia).
Seventy 1-minute exposures (70 minutes total exposure) at gain 100, taken on September 4 / 5, 2021, were added for this shot with Astro Pixel Processor (APP) software and the final image processing was done in Photoshop. Darks, flats, and darkflats were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system (field of view comparison: image of the moon with the same equipment).
