Silver Dollar Galaxy


Ron Brecher

NSW, Australia

SBIG ST-6303E camera, Astrodon Gen2 LRGB filters, Custom-built 150mm f/11.1 refractor, Paramount ME. All pre-processing and processing in PixInsight. Brett Soames acquired the data from his observatory in Bathurst, New South Wales, Australia.

8x15mR, 8x15mG, 8x15mB and 77x15mL unbinned (total = 25hr15m)

Complete image processing details available at

This galaxy, NGC253, has several nicknames: The Silver Dollar Galaxy, The Silver Coin Galaxy, and the Sculptor Galaxy. It is very low in the sky at the best of times from my location, but passes overhead from Australia, where this data was acquired. I observed this object through a 6″ telescope the last time I was in Costa Rica. Although it doesn’t show the colours that are evident in photographs, it showed quite a lot of detail, and is obvious and “bold†in the eyepiece, unlike many of the faint, barely-there galaxies I often look at. On the sky, it is almost as long as the full Moon is wide. In reality, it is about 70,000 light years wide, and about 11 million light years away. NGC253 is classified as a starburst galaxy, meaning there is active star formation occurring within it. At its centre is thought to be a supermassive black hole, having a mass more than 5 million times that of the Sun.

This image is a collaboration between me and Brett Soames, of Bathurst, New South Wales, Australia. Brett acquired the image data from his home observatory and did the pre-processing (calibration, alignment and integration). I did the processing as described below to produce this image.