Andrew Cooper
May 2, 2003    Kartchner Caverns State Park, AZ (map)
46cm f/4.5 Deep Violet

Reasonably large, very diffuse with no structure noted, core very indistinct, just a slight brightening at the center, 13th magnitude star on the NE edge, sparse field

Harold Corwin

NGC 5474 is a well-known companion of M 101 (NGC 5457). The interaction with M 101 has apparently led to the eccentric nucleus and inner arms. The peculiar nature of the galaxy was even commented on by William Herschel who found it on 1 May 1788. His published description reads, "cB, cL, n[orth] ends abruptly, s[outh] vg[radually]." In the sweep itself, he says, "cB, terminating abruptly to the north, and diffused to the south, cS." Samuel Hunter, using Lord Rosse's Leviathan on the 12th and 14th of May 1861, wrote, "Very like a comet or an annular neb with Nucl on edge" and "vL and probably of interest. The Nucl is on n edge and appears to have a dark lane around it; the F neby spreads out from it like a fan with the edges rather brighter than the center."

It might be of some interest (cf. Hunter!) to dig out other visual observations of the galaxy.

The nucleus itself is extremely faint and small, just barely visible in the SDSS image. I've measured the position from that image as the SDSS itself has the galaxy masked out so provides no astrometry or photometry. The other optical and infrared surveys do not resolve the nucleus.

― NGC Notes by Harold Corwin