IC 4604 is part of a complex of dusty, dark absorption nebula and reflection nebulae just to the north of Antares. Since IC 4604 is a reflection nebula, it is very poorly recorded in this image, which was taken using an H-alpha filter. Several other nebulae belonging to the complex were recorded however. These are indicated in the image below and the details are listed in the following table.
Number | Name | R.A. | Dec | |
1 | IC 4604 | 16 26 | -23 30 | Image |
2 | IC 4603 | 16 26 | -24 30 | |
3 | Sharpless 2-9 | 16 21 | -25 40 | |
4 | M4 | 16 27 | -26 02 | Image |
5 | IC 4606 | 16 29 | -26 00 | |
6 | IC 4605 | 16 30 | -25 05 | |
7 | Sharpless 2-1 | 15 56 | -26 00 | |
8 | IC 4592 | 16 13 | -19 20 | |
9 | IC 4601 | 16 20 | -20 10 |
Also on the image are 3 emission nebulae, indicated by the letters "a", "b", and "c". I have been unable to track down designations for these three nebulae. Most surprising was the one at the very top of the image, "c". This nebula surrounds the bright star zeta ophiuchi and is quite large, spaning over 5 degrees and so must have been cataloged by someone. It is shown fully in the image below.
Below is a mosiac of these two images.