Jewels from far Southern climes

While in Chile for the 2019 total eclipse I had the opportunity to observe with a 16″ Meade LX200 at the El Pangue observatory, which is equipped with several large telescopes for use by amateur groups. One of the highlights was the sight of this globular cluster.

47 Tucanæ is the second brightest globular cluster in the sky, the brightest being the Omega Centauri cluster, also a far-southern object. The brightest in the northern sky is M13 in Hercules.

Globular clusters are enormous cities of stars, drawn into a spherical shape by their self-gravity. They are found in a large halo surrounding the galaxy’s core, and are much bigger and far older than open clusters such as the Pleiades. The milky way has about 150 globulars in its halo and 47 Tuc is one of the largest, being about 120 light years across. It is about 13,000 light years distant and contains millions of stars. To give an idea of scale, the image above is about the same size as the full Moon.

With a declination of 72° south, 47 Tuc can never be seen from the UK and for a decent view of it one needs to travel as far south as southern Africa, Australia or, as in this case, South America. Through the eyepiece the view is stunning, the cluster almost filling the field of view.

After my trip I was able to use one of Telescope Live’s instruments to obtain an image of this spectacular object. I used their 24″ Planewave CDK reflector (see image below) located at their remote facility in the Rio Hurtado Valley, also in Chile. It took just 10 minutes’ exposure each through red, green, blue and clear filters to obtain the above image. The CDK24 is a big brother of my own scope in Spain, but with three times the light gathering power. The FLI P9000 CCD camera and Astrodon filters are the same as those on my own scope.