22 Sept 2024
These are two elliptical galaxies, NGC474 and NGC467, with tidal shells of very unique shapes. They are in the constellation Pisces. These two galaxies are far apart, so I think they just happen to overlap, but the bluish galaxy NGC470 is actually close to NGC474, and there is a theory that their gravitational interaction triggered the formation of the tidal shell of NGC474. It was fainter than I expected, and it was challenging for me to visualize well even with an exposure time of over 11 hours, but you can still see the multi-layered outer shell structure.
NGC 474
9 credit
Filter | Avg Exp (s) | Total Exposure | Subframes |
|---|---|---|---|
| Luminance | 278 | 3h5m | 40 |
| Red | 233 | 2h35m | 40 |
| Green | 330 | 3h40m | 40 |
| Blue | 360 | 4h | 40 |