Messier 33, the Triangulum Galaxy, is a face-on spiral galaxy in the constellation Triangulum and the third-largest member of the Local Group after the Milky Way and Andromeda.
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
Messier 33, the Triangulum Galaxy, is a face-on spiral galaxy in the constellation Triangulum and the third-largest member of the Local Group after the Milky Way and Andromeda. It lies approximately 2.7 million light-years away, with a true diameter of roughly 60,000 light-years. Unlike the more dramatic M31, M33 has a comparatively low surface brightness, making it more challenging to image well from light-polluted skies despite its relatively large apparent size. Its loosely wound spiral arms host numerous star-forming HII regions, most notably NGC 604, one of the largest known star-forming regions in the Local Group. M33 rewards long, dark-sky exposures that bring out its faint spiral structure and pink-tinged nebular knots.
[Source: Wikipedia, en.wikipedia.org/wiki/Triangulum_Galaxy]
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 S30 |
| Optics: | 150 mm focal length, f/5, 30 mm aperture (APO triplet) |
| Date: | 2025-12-18 |
| Number of images: | 567 |
| Exposure per image: | 30 s |
| Total imaging time: | 4 h 44 min |
PixInsight Processing
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- StarXTerminator (star removal) (x2)
- Generalized Hyperbolic Stretch (x9)
- PixelMath (x2)
- HDR Multiscale Transform
- Drizzle Integration
- Curves Transformation
