AAO image reference AAT 74. « Previous || Next »
Top left is NE. Image width is about 37 arc min
Image and text © 1987-2010, Australian Astronomical Observatory, photograph by David Malin.
Ara is a small constellation in the southern Milky Way, and devoid of bright stars. The fainter stars here are cool, like those that orbit the inner 'bulge' of the Milky Way and appear slightly yellow on colour pictures. The foreground patch of dust that crosses this photograph must be illuminated by energetic radiation from stars that are much hotter than those in the background because hydrogen, which is associated with the dust, has been excited into a vivid red fluorescence by absorbing the invisible ultraviolet light. Here and there a few bright but cooler stars are caught up in the outskirts of dust clouds and some of their light is scattered to produce the blue reflection nebulae.
Related Images
AAT 75. The NGC 6188 nebula and NGC 6193
AAT 75a. The NGC 6188 nebula and NGC 6193 (wide field)
AAT 74a. Reflection nebula in NGC 6188
Constellation of Ara (external site)
For details of photographic exposure, search technical table by AAT reference number.