Arp 305 / NGC 4016 / NGC 4017
| Designation(s) | Arp 305, NGC 4016, NGC 4017 |
| Object Type(s) | Galaxy, Galaxy Cluster |
| Relevant Catalog(s) | All (Chron), Arp, NGC |
| Arp Category | Unclassified double galaxies |
| Obs. Lat/Long | 42° 17', 073° 57' |
| Constellation | Leo |
| Date and Time Observed | 2026-03-27 23:00:00 |
| Instrument | EdgeHD 8" w/f7 reducer-1,422mm FL |
| Camera | Player One Apollo-M Mini |
| Image Details | Up is 13.9 degrees E of N. Transparency: Good. Seeing: Poor. Total integration time was 50m. Exposures 20s@225g, No Filter. Dithered and recentered in SharpCap. No guiding. |
| Description | Arp's comment on this pair of galaxies suggests he was intrigued, "Segment breaking from arm of S gal., weak filaments reach to N gal., which has figure 8 loops." My initial reaction was that we were looking at tidal debris, the legacy of a fly-by, though I was puzzled by the linear splotch, the most visible part of an incomplete debris trail connecting them, slightly closer to NGC 4017. Turns out Arp 305 has been studied recently, and that "splotch" is a cluster of Compact Dwarf Galaxies, created in the debris from the fly-by, representing areas of significant star formation. I provide links to the papers at the bottom of the page, below the gallery. A reasonable night with few clouds and decent transparency, but marred by mediocre seeing and a 74% moon. Still, I was pleased with the result. |
| Catalog Links | All Listings |
