| Designation(s) | Arp 307, NGC 2974, NGC 2973, NGC 2972 |
| Object Type(s) | Galaxy |
| Relevant Catalog(s) | All (Chron), Arp, NGC |
| Arp Category | Galaxies with concentric rings or Double Galaxies(?) |
| Obs. Lat/Long | 42° 17', 073° 57' |
| Constellation | Sextans |
| Date and Time Observed | 2025-01-26 20:10:00 |
| Instrument | EdgeHD 8" w/f7 reducer-1,422mm FL |
| Camera | Player One Apollo-M Mini |
| Image Details | Up is 359.3 degrees E of N. Total integration time was 45m. Exposures 30s@300g, UV/IR Cut Filter. Darks subtracted, no flats. Dithered and recentered in SharpCap. No guiding. |
| Description | This is a lovely cluster, but hard to interpret. Sources don't agree on how Arp categorized it: Kanape and Webb list it as "Double Galaxies" The AL list has the category as having "concentric rings" presumably referring to the lenticular galaxy NGC 2974 alone. The Cal Tech website doesn't list its category. Anyway, judging from the halos around the galaxies, which are most clear in the inverted images (either mine or Arp's) it looks to me that 2974 and 2972 are interacting, and it's ambiguous if 2973 has joined the fun. That said, Arp left a cryptic set of remarks: "Position between pair. Possibly not interacting. " It's ambiguous whether he's referring to 2972 (the medium sized elliptical) or 2973 (the small spiral). |
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