NGC/IC Project Restoration Effort

(This is a very very beta version)

NGC5257

 

Basic Information


Location and Magnitude


Right Ascension: 13:39:52.8
Declination: +0:50:25
Constellation: VIR
Visual Magnitude: 12.4

Historic Information


Discoverer: Herschel W.
Year of discovery: 1793
Discovery aperture: 18.7

Observational


Summary description: vF, S, R, bM, p of D neb
Sub-type: SBb/P

Steve's Notes

===== NGC 5257 48" (5/4/16): at 610x; very bright, fairly large, striking two armed-spiral. The central portion only extends ~35", but contains a fascinating structure. Along the southwest and northeast flanks are sharp-edged prominent "arms", appearing as thin, high surface brightness arcs, with the southern arc slightly brighter. Both "arms" are slightly convex, appearing like a close pair of parenthesis enclosing the central region! The northern arm continues as a fainter, but easily visible, fairly thin arc extending west-northwest, and ends just before reaching a mag 15 star [1.7' WNW of center]. A thin, very low surface brightness arm extends west from the southern "parenthesis" towards NGC 5258 (1.4' ESE), but stops just short. The tip-to-tip distance between the two arms is ~1.6'. On the inside of the two bright "arcs" (blue star-forming arms) there appear to be two thin dust lanes as the surface brightness drops dramatically. At the center is a fairly faint stellar nucleus. The overall appearance is very unusual as the surface brightness of the core region is lower than the thin pair of symmetrical arms. 17.5" (4/28/90): fairly faint, fairly small, oval 3:2 WSW-ENE, weak concentration. A mag 14 star is off the west side 1.7' from the center. Forms a close, interacting pair (Arp 240) with NGC 5258 1.3' SE.