| Designation(s) | Arp 112, NGC 7805, NGC 7806, KUG 2359+311 |
| Object Type(s) | Galaxy |
| Relevant Catalog(s) | All (Chron), Arp, NGC |
| Arp Category | Elliptical galaxies repelling spiral arms |
| Obs. Lat/Long | 42° 17', 073° 57' |
| Constellation | Pegasus |
| Date and Time Observed | 2024-10-28 23:19:00 |
| Instrument | EdgeHD 8" w/f7 reducer-1,422mm FL |
| Camera | Player One Apollo Mini |
| Image Details | Up is 99.1 degrees E of N. Total integration time was 20m. Exposures 15s@300g, UV/IR Cut Filter. Darks subtracted, no flats. Dithered and recentered in SharpCap. No guiding. |
| Description | A compact cluster of 3 galaxies, clearly interacting. The elliptical galaxy is NGC 7805, the largest spiral, is NGC 7806, and the small spiral in profile is KUG 2359+311. The two NGC galaxies are reasonably bright... the KUG has very low surface brightness which I can see nearly complete if I overstretch it and blow out the rest of the image. It is apparently a very strong UV emitter as it shows up on the KUG catalog, which is reserved for strong UV sources. It's unclear to me why the lower arm of NGC 7806 is so elongated. Arp categorizes it as "elliptical galaxies repelling spiral arms". Really? Seems to me that gravity attracts not repels. Remarks are blank for Arp 112, so no clues there. An alternative explanation might be that one of the other galaxies passed below from right to left before being captured and pulled back into the current orientation. The extended arm, therefore, might be a legacy of the "fly by". In any event, the two larger galaxies are close to each other and clearly exchanging matter. The KUG may be interacting with the spiral, judging from my inverted capture. |
| Catalog Links | |
