NGC/IC Project Restoration Effort

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NGC5474

 

Basic Information


Location and Magnitude


Right Ascension: 14:5:1.4
Declination: +53:39:46
Constellation: UMA
Visual Magnitude: 10.8

Historic Information


Discoverer: Herschel W.
Year of discovery: 1788
Discovery aperture: 18.7

Observational


Summary description: pB, L, bM
Sub-type: Sc

Corwin's Notes

===== 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 WH 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 LdR'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.

Steve's Notes

===== NGC 5474 18" (4/26/08): at 220x this is a fairly bright, large, asymmetric galaxy ~3.0'x2.5'. The galaxy is moderately concentrated with an 0.8' core that is embedded at the north end of the galaxy! The halo of the galaxy is a slightly elongated N-S oval glow with the core internally tangent on the north side. 18" (6/17/06): fairly bright, large, with an irregular asymmetric appearance. Broadly concentrated to a 1' brighter core that resides on the north edge of the galaxy. The 2.5' halo is slightly elongated N-S and spreads out from the core only towards the south! The halo has a slightly mottled texture and fades at the periphery. With averted vision the size increases to nearly 3'. A mag 13.5-14 star is just north of the offset core. A mag 13 pair at 14" lies 9' ESE. This disturbed galaxy is a member of the M101 group. 17.5" (5/22/93): fairly bright, large, irregular round or slightly elongated SSW-NNE. Very unusual appearance as a large brighter knot of 0.8' diameter or a very eccentrically placed core is located at the NE edge. The halo extends generally SW from this brighter spot. About 3' diameter, no brightening at the geometric center. A mag 14 star is just off the NE edge 0.8' beyond knot. Located 45' SSE of M101 and the asymmetry is from being tidally deformed by M101.