Arp 185:

North is left. 0.35"/pixel (7.7' by 20' field). FWHM = 5.5"

Arp filled this under "galaxies with narrow filaments", but I don't really see why. It's a barred sprial with irregular arms and a faint extended disk.

That being said, the galaxy's bar is slightly misaligned with the core:

which would sudgest that it might have experienced some graviational interaction in the past.

The main galaxy is at z=0.0045, and the faint background galaxy in the lower left is UGC 10509 at z=0.055. It's actually a spiral with a really intresting structure, but it's too small (and dim) to see in my image.

Total exposure time: 274 * 30 seconds = 2.2 hours.

Telescope: C9.25 (230mm, f/10, fl=2300mm)

Camera: IMX533 (16mm diagonal, square, color)

Processing:

1. Callibration (dark + flat)

2. Stacking (average w/ rejection)

3. White balance and background subtraction

4. Asinh stretch

5. Tone curve

6. Crop

Taken during a night with exceptionally bad seeing, resulting in a FWHM of 5" instead of the usual 3". Not that I ever get good seeing, presumably due to nearby heat sources: My telescope was set up between a asphalt road and asphalt roof.

Both of these get super hot during the day and retain that heat all night.

Related:

• /astro/arp185/stacked.fits.fz: Raw stacks.

• ned.ipac.caltech.edu/level5/Arp/Figures/big_arp185.jpeg: Arp's image.