...A celestial wonderland of innumerable star cities, twinkling across the millions of light years.--Robert Burnham
This part of the sky used to be called the Realm of the Nebulae because of the high concentration of deep sky objects here. Back in those days, not so long ago, astronomers had not yet realized that some faint fuzzies were clouds of gas within our own galaxy, and others were gigantic collections of stars, gas and dust similar to the Milky Way itself.
It's easy to get lost in the Virgo Cluster. Finding and identifying the many Messier objects here is a good exercise in keeping your bearings at the eyepiece. After logging the galaxies that Messier found, and tracing out Markarian's Chain, what next? Check out some of these galaxy pairs that are among my favorite objects in the Virgo Cluster. (The observing notes are by Steve Gottlieb.)
The Eyes (NGC 4435/38)
This is one of the most prominent links in Markarian's Chain, lying just 20 arcminutes east of M86. A famous observer from the last century, L.S. Copeland, gave this interacting pair its nickname. Actually, there is some question whether NGC 4438 is really interacting with NGC 4435. According to Brian Skiff, NGC 4438 is probably a mostly-merged pair of galaxies, but 4435 is utterly undisturbed, and I'm quite willing to bet the next round of beers that it has nothing to do with 4438.
N4435 = U07575 = M+02-32-064 = VV 188 = The Eyes
12 27.7 +13 05
17.5: bright, fairly small, oval SSW-NNE, bright core, stellar nucleus.
Forms a striking pair called the "Eyes" with slightly fainter N4438 4.5'
SSE. Located 20' E of M86 in the central core of the Virgo cluster.
N4438 = U07574 = M+02-32-065 = Arp 120 = VV 188 = The Eyes
12 27.8 +13 01
17.5: bright, elongated 5:2 SSW-NNE, small bright core. Forms a striking pair
with N4435 4.5' NNW. The core is not as large or bright as N4435. Located in
the center of the Virgo cluster 23' E of M86.
The Siamese Twins (NGC 4567/68)
Look two degrees southeast of M87 to find this fascinating pair of interacting galaxies joined at the eastern end. (I love these wonderful old nicknames from the nineteenth century, don't you?) In fact, the Siamese Twins may not be interacting at all. According to a recent article from the professional journals, There are numerous H-Alpha regions spread out across the surfaces of both NGC 4567 and NGC 4568. However, the general lack of
tidal tails, x-ray emission, or discernible tidal signatures in the nuclear regions all argue that the galaxies are not interacting.
N4567 = U07777 = M+02-32-151 = Siamese twins = VV 219
12 36.5 +11 16
17.5: northern member of a double system with N4568. Moderately bright,
fairly small, elongated 3:2 ~E-W. Slightly smaller than N4568 attached at
the E end but has a slightly higher surface brightness.
13: fairly faint, elongated E-W. N4568 is attached at the NE end.
N4568 = U07776 = M+02-32-152 = Siamese twins = VV 219
12 36.6 +11 14
17.5: this is the southern member of a double system with N4567. The NE
end of this galaxy is nearly attached to the E end of N4567. Moderately
bright and large, elongated 5:2 SSW-NNE, large brighter core. Two mag
11/12 stars lie 3.5' E.
From the Siamese Twins it's another two degrees east to M60 and its companion,
and 2.5 degrees further east to another nice pair, including a very thin edge-on.
N4754 = U08010 = M+02-33-030
12 52.3 +11 19
17.5: bright, fairly small, slightly elongated halo SSW-NNE, 3' diameter.
Sharply concentrated with a very bright small round core containing a
substellar nucleus. Located in the center of a group of six faint mag 14
stars. A brighter mag 11 star lies 3.1' SW of center. Forms a pretty pair
with N4762 11' SE.
N4762 = U08016 = M+02-33-033
12 52.9 +11 14
17.5: very bright, fairly large, beautiful edge-on 12:1 SW-NE, 6.0'x0.5',
small intensely bright core, stellar nucleus. The unusually thin arms
taper at the ends. The galaxy appears to have a sharper light cut-off
possibly due to a dust lane along the W side. Located almost midway
between two 9th magnitude stars (SAO 100313 3.9' WSW and a mag 9.5 star
2.8' E). Forms a pair with N4754 11' NW.
Sweeping to the northwestern part of the cluster, just east of M99 is another impressive pair, a bright edge-on beside an elliptical. Can you see the dust lane in NGC 4302?
N4298 = U07412 = M+03-32-007
12 21.5 +14 36
17.5: fairly bright, moderately large, elongated NW-SE, broadly brighter center. A mag 13 star is at the E end 0.8' from center. Forms a close pair with edge-on N4302 2' E.
13: fairly faint, slightly elongated NW-SE. A mag 13 star is at the E end.
N4302 = U07418 = M+03-32-009
12 21.7 +14 36
17.5: fairly faint, large edge-on 7:1 N-S, 4.5'x0.6', low surface
brightness, weak concentration. A mag 14 star is off the N edge 2.0' from center. Forms a close pair with N4298 2.4' W.
13: faint edge-on streak N-S close following N4298.
About two degrees southwest of M99 lie three more edge-on spirals in the same wide field.
N4206 = U07260 = M+02-31-066 = IC 3064
12 15.3 +13 01
17.5: fairly faint, edge-on 6:1 exactly N-S, 4'x0.7', fairly large, weak
concentration. A mag 12 star lies 2.9' SE of center. N4216 lies 10' NE
and N4222 is 23' NE. First of three edge-ons in a low power field!
N4216 = U07284 = M+02-31-072
12 15.9 +13 09
17.5: very bright, very large, edge-on 5:1 SSW-NNE, small very bright core. A mag 14 star is close E of the core. This is a striking galaxy and is the second of three edge-on galaxies in field with N4206 11' SW and N4222 12'NE in Coma Berenices.
N4222 = U07291 = M+02-31-075
12 16.4 +13 19
17.5: faint, moderately large, edge-on SW-NE, very thin. A mag 15 star is at the E end. Located 5' W of mag 8.7 SAO 100016. This is the third of three edge-ons with N4206 23' SW and N4216 12' SW in Virgo.