AAO image reference AAT 38a. « Previous || Next »
Top left is NE. Image width is about 58 arc min
Image and text © 1999-2010, Australian Astronomical Observatory, photograph by David Malin.
These two star-formation regions appear side by side in Carina and seem to be linked as parts of an extensive nebula. However, the apparent intimacy is line-of-sight effect because these two objects are at quite different distances from the Sun. The curious looped nebula NGC 3576 is about 7000 light years from us while its neighbour NGC 3603 is more than twice as far away. That NGC 3603 is the more distant is confirmed by its colour, which is a ruddier red than the pinkish hue of NGC 3576. The change in colour is due to absorption of the blue-light component of the nebulosity by dust particles in the much longer line of sight. This effect is known as interstellar reddening, though it would be better described as 'de-blueing'. It is also seen in the Horsehead nebula.
The wider field shows the calibration step wedges that are imprinted during the exposure of the plates that made the image to provide photometric and colour balance information. Some care has be taken with these images to show them in their true colours.
AAT 38. NGC 3576 and NGC 3603
AAT 39. The loops of NGC 3576
AAT 40. Reddened nebulosity in NGC 3603
Constellation of Carina (external site)
For details of photographic exposure, search technical table by AAT reference number
| emission nebulae
| reflection nebulae
| dark nebulae
| planetary nebulae
| star clusters
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