AAO image reference AAT 85a. « Previous || Next »
Top left is NE. Image width is about 32 arc min
Image and text © 2001-2002, Anglo-Australian Observatory, photograph by David Malin.
This object derives its name from its looped shape reminiscent of the Greek letter when the nebula is seen in a telescope. The gas cloud is unusual in that it does not appear to be illuminated by the bright stars that commonly found in emission nebulae such as this. However, the nebulosity is very bright, so the exciting stars must be hidden within the cloud, an idea confirmed by the infrared brightness of the nebula. As well as exciting the nebula we can see, the embedded stars heat the dust that surrounds them, so M17 is one of the brightest objects in the infrared sky. It is about 6000 light years distant.
Entry from NGC 2000.0 (R.W. Sinnott, Ed.) © Sky Publishing Corporation, 1988:
IC 4706 18 19.6 -16 01 d Sgr *9.2 in S neb, conn with M17 IC 4707 18 20.1 -16 01 d Sgr *9.4 in S neb, conn with M17 NGC 6618 C+N 18 20.8 -16 11 s Sgr 46. 6.0 !!!, B, eL, eiF, 2 hooked; = M17Related Images
AAT 85. Messier 17, NGC 6618, the Omega nebula
UKS 22. The Milky Way south of Messier 17
For details of photographic exposure, search technical table by AAT reference number.