Globular Cluster, 47 Tucanae

Arguably the finest object of its kind in the sky and easily visible to the naked eye, 47 Tucanae is a spectacular sight even in 15cm class telescopes. It then resolves easily into hundreds of the most delicate cream-coloured stars surrounding a dense unresolved core. It is located in the southern constellation of Tucana and, by coincidence, just happens to lie close to the line of sight of the Small Magellanic Cloud (SMC), to which it is not associated, being much closer at 16,000ly away. 47 Tucanae is about 120ly across, contains an estimated 3 million stars and at 13 billion years old is almost as old as the Universe itself. It has a mass of around 7x105 solar masses and is classified as III (strong inner core of stars) on the Shapley-Sawyer globular cluster concentration scale (1927).

Close inspection of the image reveals at least one smaller partly-resolved cluster of stars; one of the globular clusters of the SMC, some 240,000ly away.


Camera: SBIG STL11000M, Astrodon filters Scope: Takahashi TOA-130, f=1000mm, f7.7, fov=1.0x0.7
Mount: Takahashi EM-200 Temma2 Guiding: external (E-finder)
Filters/Exposures: R:G:B = 11:13:12min = 36m Location: ASV's LMDSS, Lady's Pass, Victoria, Australia
Date: February 2016 Processing: CCDStack2, RegiStar and Photoshop CS5