IC 4604 is a reflection nebula surrounding the multiple star system Rho Ophiuchi, near the Antares region on the Ophiuchus/Scorpius border.
Click the image to zoom in (4 steps), then again for full view · hover to see it annotated · open full resolutionAnnotated image · click to zoom in (4 steps), then again for full view · open full resolutionSky location chart · click to zoom in (4 steps), then again for full view · open full resolution
IC 4604 is a reflection nebula surrounding the multiple star system Rho Ophiuchi, near the Antares region on the Ophiuchus/Scorpius border. It forms part of the larger Rho Ophiuchi cloud complex (also including IC 4603, IC 4605, and the dusty nebulosity around Antares itself), one of the closest active star-forming regions to the Sun, with distance estimates generally in the range of about 400-560 light-years. The region is prized by astrophotographers for its striking color palette: blue reflection nebulosity around Rho Ophiuchi, yellow-brown dust clouds, and the reddish glow associated with nearby Antares, all threaded with dark Barnard dust lanes. Because the nebulosity is faint and covers a wide field (roughly 4.5 by 6.5 degrees), it favors wide-field broadband imaging from a dark sky site over narrowband techniques.
[Source: general astronomical references, incl. deepskycorner.ch and Wikipedia Rho Ophiuchi cloud complex]
Annotated Image
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Sky Location
The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.
Image Details
| Moon Phase: | New Moon |
|---|---|
| Camera: | Seestar S50 Pro (4K Sony IMX585 sensor) |
| Optics: | 260 mm focal length, f/5.2, 50 mm aperture |
| Filter: | IRCUT |
| Binning: | 1x1 |
| Stacking: | StackingWizard, 20 frames |
| Date: | 2026-09-11 |
| Number of images: | 20 |
| Exposure per image: | 60 s |
| Total imaging time: | 20 min |
AstroWizard Processing
- GraXpert background extraction (0.5)
- Flatten sky background
- Color calibration
- BlurXTerminator (0.6)
- NoiseXTerminator (linear, 0.9) (x2)
- NoiseXTerminator (linear, 0.6) (x2)
- Stretch (normal)
- Stretch (normal) (starless)
- Star removal (StarXTerminator)
- Darken background (x3)
- Contrast (pop) adjustment
- Curves adjustment (x4)
- Saturation adjustment
- Adj dmg
- SCNR (green noise removal)
- Star recombination (screen blend)
- Crop
- Crop (starless)
