BNGC 21. Centaurus Near And Far

By Steve Mencinsky, 1998

For the famous trip to the Mt Stromlo library, we had several targets for close inspection on the ESO Schmidt plates in the category "things that are nice to look at on deep plates"

One of these was Omega Centauri. However, to our delight and surprise, there were a number of relatively bright galaxies within less than a degree of this most famous of Southern globulars, bright enough that their cores appeared completely burnt out on the Schmidt plates.

Two of these galaxies were indeed relatively bright, succumbing to the 46cm telescope from suburban Wyong, under a sky very similar to Mt Bowen in terms of darkness. These galaxies are the two elongated open shapes shown in the diagram. Nothing more than faint long smudges with bright centres, but clearly visible. The third galaxy, shown as a small open circle, was overlooked on the first observations so has in fact not been seen. However, the density of the image on the plates suggest that it too should be visible with - for example - the Society's 17.5" scope, hence it has been included on this diagram. The stars on the diagram are as per Uranometria II, map 403.

Your correspondent finds it intriguing to compare these two galaxies with the single NGC galaxy visible near M13. The geometry, relative sizes and brightnesses are quite similar. An interesting coincidence, but surely nothing more.