NGC/IC Project Restoration Effort

===== NGC 4321 = M 100. See NGC 4322, NGC 4323, NGC 4327, and NGC 4579.

===== NGC 4321 48" (4/18/15): stunning view of this gorgeous spiral at 375x and 488x. M100 is sharply concentrated with an intensely bright circular nucleus. Two prominent, high contrast arms (fairly narrow) each rotate ~270¡ and can be clearly traced to within 1' of the center. The south and north outer tips of the arms are between 5.5'-6' apart with the overall size ~6'x5'. One arm begins off the WNW side of the core with a bright mottled section angling nearly north-south for ~25". This section contains multiple HII sites NGC 4321:[HK83]220/223/229/230 from Hodge and Kennicutt's 1983 "An Atlas of H II regions in 125 galaxies". The arm curls clockwise around the south side. A small (~8" dia.) HII knot (#160/171/172) is within this arm, 1.0' S of center. Just to the east [1.5' SE of center] is a brighter, mottled section that contains a close pair [18" separation] of compact HII knots (#110 and #69/87). The surface brightness of the arm abruptly drops as it shoots due north on the east side of the halo for ~3'. The arm dims further as it curves west on the northeast side of the outer halo and ends just southeast of mag 15 star situated 2.9' NNW of center. The second arms begins ~1' SE of center with a thicker, much brighter region. The Hodge-Kennicutt Atlas catalogues numerous HII designations in this region, but none stood out individually. The arm sharply abruptly narrows and rotates clockwise around the north side of the core towards the west. It passes just south of two mag 15.5 stars, where there is a slightly brighter mottled section containing HII regions #252/253. The arm dims significantly as it heads south on the west side of the halo. Finally, it weakens further and spreads out at the end on the southwest side of the galaxy [2.6' from center]. 18" (5/15/10): very bright, large, ~4.0-4.5' diameter, sharply concentrated with a very bright round core. Spiral structure was evident at 220x with a spiral arm attached on the southwest side of the core region. This arm sweeps east on the south side, heading in the direction of a mag 14 star just off the southeast end of the galaxy, but bending north. On the north side off of the core, a portion of the inner spiral arm is visible oriented E-W and extending to the northwest of the core region. 17.5" (5/23/87): bright, very large, almost round, well-defined bright core surrounded by a large, fainter halo. Two faint galaxies NGC 4323 and NGC 4328 lie 5' N and 6' E, respectively. This is the brightest spiral in the Coma-Virgo cluster.