NGC/IC Project Restoration Effort
(This is a very very beta version)
NGC4558
Basic Information
Location and Magnitude
Right Ascension: 12:35:52.6
Declination: +26:59:30
Constellation: COM
Visual Magnitude: 14.7
Historic Information
Discoverer: Herschel J.
Year of discovery: 1827
Discovery aperture: 18.3
Observational
Summary description: vF, nf of 2 or ? 3
Sub-type: S
Corwin's Notes
=====
NGC 4558. Discovered by John Herschel north-following NGC 4556 (found by his
father), and given a position 6 seconds following and two arcmin south of the
true position, its identification is nonetheless clear as Dreyer gave
d'Arrest's micrometrically measured position more weight than Herschel's. The
NGC position is only 2 seconds and 0.8 arcmin from the true position. This
has not prevented its misidentification in MCG and PGC. MCG gives the name
NGC 4557 (which see) to it; PGC follows suit, and tries to save the number
4558 by applying it to IC 3556. Both catalogues are wrong. Wolf's
identification in the Konigstuhl Nebel-List No. 4 is correct.
Steve's Notes
=====
NGC 4558
18" (5/12/07): faint, very small, round, 20"-24" diameter, slightly brighter core. Symmetrically placed on the opposite side of a mag 13 located at the midpoint of NGC 4556 and NGC 4558. Located 5.2' NNE of NGC 4556 in a small group. IC 3556 lies 2' SE and appeared very faint, small, slightly elongated N-S, 20"x15". IC 3559 is 2.4' E, but with mag(B) = 16.6, it was only glimpsed knowing the exact location.