Two clusters for the price of one

NGC104 (47 Tucanae) is the second brightest globular cluster in the sky after Omega Centauri. Globular clusters are massive concentrations of ancient stars that are some 12 billion years old. This cluster contains over a million stars within a diameter of 120 light years with a very compact core and is 13,400 light years distant.

Also captured within the image is NGC121 although it’s a little difficult to see in this compressed web image. It’s at the bottom of the frame, just to the right of centre, (click for the larger image and it looks like a slightly larger star). It’s a lot further away as it’s not associated with our galaxy but the Small Magellanic Cloud. Subsequently it’s very faint at magnitude 10.6.

The telescope used is GRAS-10; a Tec 140 f/7 refractor with an SBIG STL-11000M-ABG, 11 mega-pixel camera and is a single 5 minute exposure.

A half size TIFF copy of the original is available here: http://www.littlebeck.org.uk/Images/NGC104.tif

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