(= NGC 7089)
|Aqr||21h33m / -00°49'||16'||6.3mag|
|The globular cluster Messier 2 (NGC 7089) in the constellation of Aquarius on
August 31 / September 1, 2019 and on September 3 / 4, 2019. Messier 2 is one of the largest known globular clusters. It is about
55,000 light-years distant from Earth and 175 light-years in diameter. Messier 2 contains about 150,000 stars. It was discovered
by the French astronomer Jean-Dominique Maraldi in 1746 and rediscovered by Chares Messier in 1760 (source: Wikipedia).
Sixty-one exposures of approximately 3 minutes and twenty exposures of approximately 60 seconds, all at ISO 800, were added with the DeepSkyStacker software and then edited in Photoshop (theoretically resulting in a 3 hours and 24 minutes exposure). However, a large percentage of the exposures showed a slight blur due to focusing errors and / or a tendency towards star trails due to tracking errors. Under ideal circumstances, a total exposure time of one hour would show a similar or better result.
|Equipment: Canon EOS 450Da camera, TeleVue ParaCorr Type II coma corrector, 16" f/4.5 dobsonian telescope "Ninja" 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).|
Search chart for Messier 2. Map © 2019 "The Mag-7 Star Atlas Project", www.siaris.net. Map is slightly modified. The map can be downloaded here .