Arp 199 / NGC 5544-5

Designation(s)Arp 199, NGC 5544, NGC 5545
Object Type(s)Galaxy
Relevant Catalog(s)All (Chron), Arp, NGC
Arp CategoryGalaxies with material ejected from nuclei
Obs. Lat/Long42° 17', 073° 57'
ConstellationBootes
Date and Time Observed2025-09-21 21:07:00
InstrumentEdgeHD 8" w/f7 reducer-1,422mm FL
CameraPlayer One Apollo-M Mini
Image DetailsUp is 274.0 degrees E of N. Transparency: Fair. Seeing: Good. Total integration time was 45m 30s. Exposures 15s@300g, No Filter. Dithered and recentered in SharpCap. No guiding.
DescriptionThese two galaxies were discovered by William Herschel on a very productive night in 1785. He originally classified it as a single galaxy. 40 years later his son, John, saw them clearly enough to separate them into two. Arp found the interaction interesting, but seemed to focus on "material ejected from nuclei".

The Atlas plate (left in the comparison) shows a series of black dots near the glowing nuclei of both galaxies. They should show up in my positive image as bright spots. Given how dark these dots are in Arp's image, its surprising to me that these objects aren't more prominent in my capture. The only obvious corresponding bright spots are located towards the top of NGC 5545. I think it's equally likely that this material was stripped off one or the other of the galaxies as they intersected with each other.
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