NGC 7331 is a large, unbarred spiral galaxy in the constellation Pegasus, located roughly 39-40 million light-years away and often cited as one of the closest visual analogs to our own Milky Way in overall size and structure.
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NGC 7331 is a large, unbarred spiral galaxy in the constellation Pegasus, located roughly 39-40 million light-years away and often cited as one of the closest visual analogs to our own Milky Way in overall size and structure. Discovered by William Herschel in 1784, it is inclined steeply to our line of sight, showing an elongated disk, a prominent central bulge, and a dust lane along one edge; unusually, its bulge is known to rotate in the opposite direction to its outer disk. NGC 7331 anchors a loose foreground grouping nicknamed the Deer Lick Group, sharing the field with several much fainter, far more distant background galaxies (NGC 7335, 7336, 7337, and 7340) that appear nearby only by chance alignment. It is a popular wide-field target alongside the more distant compact cluster known as Stephan's Quintet, roughly half a degree away.
[Source: Wikipedia, en.wikipedia.org/wiki/NGC_7331; Wikipedia, en.wikipedia.org/wiki/NGC_7331_Group]
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: | First Quarter |
|---|---|
| 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, 57 frames |
| Date: | 2026-09-18 |
| Number of images: | 57 |
| Exposure per image: | 60 s |
| Total imaging time: | 57 min |
AstroWizard Processing
- Crop (x2)
- GraXpert background extraction (0.5)
- Flatten sky background
- Color calibration
- BlurXTerminator (0.3)
- NoiseXTerminator (linear, 0.6) (x2)
- Stretch (deep)
- Stretch (deep) (starless)
- Star removal (StarXTerminator)
- Darken background (x3)
- Saturation adjustment
- Contrast (pop) adjustment
- NoiseXTerminator (non-linear, 0.6)
- Star recombination (screen blend)
