AAO image reference AAT 95. « Previous || Next »
Top left is NE. Image width is about 2.5 arc min
Image and text © 1995-2010, Australian Astronomical Observatory, photograph by David Malin.
This is an unusual annular planetary nebula in Norma. The nebula itself appears quite small at a little over an arc minute in diameter, while its central star is a magnitude 14 white dwarf. This object is unusual because those planetaries that are not bipolar are more or less spherical shells of material thrown off by the central star as it undergoes an internal rearrangement. We often see them as thick annuli because we look through a greater thickness at the edge of the shell. However, Shapley 1 seems to be a true torus, a doughnut-shaped ring of material that we happen to see face-on around the central star. Sp-1 is about 1000 light years distant.
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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