M 100 (NGC 4321) Galaxy in Coma Berenices

Located at: RA 12 hours 22 minutes 55 seconds, Dec +15 degrees 49 minutes 25 seconds

Size: 7.5' x 6.3' Magnitude: 10.1 blue Class: SAB(s)bc HII

North is up

West to the right

Telescope:

 8" f5 Newtonian reflector

Camera:

 ST-8XME, self-guided, binned 1x1, temp -20c & -25c, camera control MaxIm DL 4.56

Image:

Lumicon Deep Sky filter, 540 minutes (54 x 10 minute subs), 05/30/31 & 06/1/2008; seeing 2.0-2.7 FWHM per CCDStack

Processing:

CCDStack 1.3.7, Photoshop 7.0

Location:

 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes:

See the 14.5" f5 Kodak hypered Tech Pan 2415 film image of this lovely spiral galaxy in Coma, that was being imaged from Mt Pinos when the 1994 Northridge earthquake struck. See the 14.5" version.

Above M 100 and slightly to the east (upper left) is NGC 4323 (1.2'x0.8', 14.0v mag, Cl:SB(r)0^:), and due east (left) is NGC 4328 (1.3'x0.9', 14.0b mag, Cl:SA0-:). To the west (right) are several IC objects ...

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 4321

NGC 4321 = M100 = U07450 = MCG +03-32-015 = CGCG 099-030 = PGC 40153
12 22 55.0 +15 49 21
V = 9.3;  Size 7.4x6.3;  SB = 13.4;  PA = 30d

17.5": bright, very large, almost round, well-defined bright core surrounded by 
a large, fainter halo.  Two faint galaxies N4322 and N4328 lie 5' N and 6' E, 
respectively.  This is the brightest spiral in the Coma-Virgo cluster.

- by Steve Gottlieb
Historical Research Notes / Correction for NGC 4321
NGC 4321.  See NGC 4322, NGC 4323, and NGC 4327.
 - Dr. Harold G. Corwin, Jr.
Historical Research Notes / Correction for NGC 4322
NGC 4322 is probably a star.  It, NGC 4323, and NGC 4327 were all found by 
Tempel while he was observing NGC 4321 (M 100) and NGC 4328.  He only gives 
descriptive places for them with respect to the brighter objects, so the NGC 
positions are only approximate.  His entire note for the three objects reads
(translation by me), "... on my drawing, there are three other very faint 
nebulae in the vicinity, two north of and close to 2890 [N4321], and the third 
south of 2894 [N4328]."

Given Tempel's propensity for seeing nebulae where only stars exist, I think
that the star northwest of M100, and one of the stars southeast, along with 
the galaxy to the northeast, are Tempel's three objects.  It's certainly 
possible to argue with this since Tempel gives no details about the appearance 
of his objects, but this is a reasonable hypothesis under the circumstances.

The galaxy to the northeast has been called "NGC 4322 = NGC 4323" by many 
observers.  Since Tempel's description is very clear about his having seen two
"nebulae" north of M100, the identity cannot be true.  This has the 
unfortunate consequence that the number 4322 is put onto a star, but I prefer
this to inverting the RA order. - Dr. Harold G. Corwin, Jr.
Historical Research Notes / Correction for NGC 4323
NGC 4323 is the galaxy northeast of M100 (= NGC 4321) that has been called
"NGC 4322 = NGC 4323" in many catalogues and lists.  See NGC 4322 
for the story on this. - Dr. Harold G. Corwin, Jr.
Contemporary Visual Observation(s) for NGC 4328
NGC 4328 = MCG +03-32-019 = CGCG 099-034 = Ho 387d = PGC 40209
12 23 20.0 +15 49 13
V = 13.0;  Size 1.3x0.9;  SB = 13.1;  PA = 90d

18" (4/5/03): very faint, fairly small, slightly elongated ~E-W, 0.8'x0.6', very 
low surface brightness (although catalogued sfc br is 13.1), very weak 
concentration.  A mag 14.5 star lies 1.4' NE.  Located 6.0' E of M100.

17.5": extremely faint, small, round.  A mag 14.5 star is 1.4' NE of center.  
Located 6' due E of M100!

- by Steve Gottlieb
Historical Research Notes / Correction for NGC 4328
NGC 4328.  See NGC 4322, NGC 4323, and NGC 4327. - Dr. Harold G. Corwin, Jr.