Arp 42 – NGC 5829 with IC 4526
| Designation(s) | Arp 42, NGC 5829, IC 4526 |
| Object Type(s) | Galaxy |
| Relevant Catalog(s) | All (Chron), Arp, IC, NGC |
| Arp Category | Spiral galaxies with low surface brightness companion on arms |
| Obs. Lat/Long | 42° 17', 073° 57' |
| Constellation | Bootes |
| Date and Time Observed | 2025-07-22 23:25:00 |
| Instrument | EdgeHD 8" w/f7 reducer-1,422mm FL |
| Camera | Player One Apollo-M Mini |
| Image Details | Up is 358.2 degrees E of N. Transparency: Good. Seeing: Good. Total integration time was 58m. Exposures 15s@300g, No Filter. Dithered and recentered in SharpCap. No guiding. |
| Description | Arp clearly felt these two galaxies are interacting. He left, for him, a verbose set of remarks: "Faint bifurcated arm to companion, one faint arm on companion coiled same direction as parent". Why he felt it was important that the companion was coiled in the same direction is unstated. And, of course, reading this before observing, a key objective for me was to make sure my observation captured the "faint arm" on the companion. That turned out to be very challenging. The arm is truly faint, and I saw NOTHING until about 50 minutes into the observation, which is an enormous amount of integration given the sensitivity of the Apollo M-mini camera. In this presentaiton you're seeing the image after additional processing, so it may not seem so obscure. I, of course, was planning to continue collecting lights as long as necessary, but clouds put an end to that dream. If you believe red shifts (Arp didn't always), IC 4526 is more than 300 million light years further than NGC 5829, so the appearance of interaction is likely an illusion. NGC 5829 is not, however, one of the galaxies Arp uses to debunk the reliability of redshift as a distance measurement in his book, "Seeing Red". |
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