Apparent size 3.5 by 1.0 arcmin. Listed as a member (VCC 1619) of the Virgo Cluster.

Apparent size 2.2 by 1.6 arcmin. Listed as a member (VCC 1630) of the Virgo Cluster.

Historical Identification: Per Dreyer, NGC 4552 (= GC 3097 = JH 1348, M89, 1860 RA 12 28 36, NPD 76 40.3) is "pretty bright, pretty small, round, gradually much brighter middle". The position precesss to RA 12 35 40.3, Dec +12 33 23, essentially dead center on the galaxy listed above and the description fits, so the identification is certain.
Physcial Information: Apparent size 3.8 by 3.3 arcmin; fainter outer regions cover about 8.8 by 7.2 arcmin. Listed as a member (VCC 1632) of the Virgo Cluster.

Apparent size 2.4 by 1.5 arcmin. (Need size of brighter inner region, and fainter outer outline, from images below)
Use By The deVaucouleurs Atlas: NGC 4553 is used by The deVaucouleurs Atlas of Galaxies as an example of type SA(r)0⁺ (whence the type shown above).

Per Dreyer, NGC 4554 (Temple list V, 1860 RA 12 28 37, NPD 78 02.5) is "very faint." The second IC adds "Not found by Frost on plate of 4 hours exposure." The position precesses to RA 12 35 41.9, Dec +11 11 11 (whence the position above), but there is nothing there. Corwin suggests (and Steinicke agrees) that the pair of magnitude 13.4 and 13.6 stars at RA 12 35 59.5, Dec +11 15 55 (about 6 arcmin northeast of the NGC position) might be what Tempel observed, then points out that for that to be true Tempel's recorded offsets from NGC 4567/8 (which are well to the left of the field of view shown below) would have to be off in both direction and size. Since that isn't likely, the double star is almost certainly not NGC 4554, and the NGC entry almost certainly represents a lost or (more likely) nonexistent object.

Historical Identification: Per Dreyer, NGC 4555 (GC 3099 = JH 1350 = WH II 343, 1860 RA 12 28 43, NPD 62 42.3) is "bright, pretty small, irregularly round, very suddenly much brighter middle equivalent to 12th magnitude star". The position precesses to RA 12 35 40.0, Dec +26 31 23, right on the galaxy, so the identification is certain.
Note About Duplicate Entry: As noted in the entry for IC 3545, Wolf mistook the galaxy to the south of NGC 4555 (PGC 1777936) for NGC 4555 itself, so he thought that the brighter northern object was a new discovery, and Dreyer failed to realize that Wolf's position and description were essentially identical to Herschel's, so NGC 4555 ended up in both the NGC and IC2.
Physical Information: Apparent size 2.1 by 1.4 arcmin? As it happens, PGC 1777936) is not only historically important (as the cause of the duplicate entry), but is probably a physical companion of NGC 4555 as well, so it is discussed in the following entry.

Physical Information: Based on a recessional velocity relative to the Cosmic Background Radiation of 7025 km/sec (and H₀ = 70 km/sec/Mpc), a straightforward calculation indicates that PGC 1777936 is about 325 to 330 million light-years away, in reasonable agreement with a single redshift-independent distance estimate of about 355 to 360 million light-years. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 315 to 320 million light-years away at the time the light by which we see it was emitted, about 320 to 325 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.45 by 0.3 arcmin (from the images below), the galaxy is about 40 to 45 thousand light-years across. As it happens, PGC 1777936's northern neighbor, NGC 4555, has a similar recessional velocity and an identical redshift-independent distance estimate, so they are probably physical companions.

WORKING HERE: The region near NGC 4556 contains a number of frequently misidentified galaxies; for that reason it will take some time to sort out everything, and complete posts for NGC 4556 - 4563

Per Dreyer, NGC 4556 (GC 3100 = JH 1351 = WH II 380, 1860 RA 12 28 46, NPD 62 18.8) is "faint, pretty large". The position precesses to RA 12 35 42.7, Dec +26 54 53, just northwest of the galaxy and there is nothing else near enough to cause any confusion, so the identification is certain. Despite that (per Corwin) there were some ghastly blunders involving NGC 4563 in modern catalogs that resulted in misidentifications involving IC 3556, NGC 4536 and 4556 (more to follow per Corwin). Apparent size 1.5 by 1.1 arcmin.

Per Dreyer, NGC 4557 (Bigourdan (list II #55), 1860 RA 12 28 53, NPD 62 11.5) is a "nebulous star". The position precesses to RA 12 35 49.6, Dec +27 02 11, an arcmin south of a scattering of faint stars, including the triplet listed above. Per Corwin, Bigourdan's offset relative to NGC 4558 clearly places the object close to the triplet, and the description makes its identification as a stellar object certain. He adds that Wolf clearly observed it as the central of three stars, and therefore uses that star's position for the NGC object, but since Bigourdan must not have resolved the stars he considers the triplet to be object, not just the central star. Corwin notes that the MCG and PGC identifications are wrong (and as a result, so are a number of listings for NGC 4557); for that reason, see NGC 4558.

See Corwin. (Often misidentified as NGC 4557; in addition, IC 3556 is often misidentified as NGC 4558.) Apparent size 0.85 by 0.75 arcmin.

Based on a recessional velocity of 815 km/sec, NGC 4559 is about 38 million light years away. Although peculiar (non-Hubble expansion) velocities could be a substantial part of the recessional velocity, the distance is in good agreement with redshift-independent distance estimates of 25 to 50 million light years. Given that and its apparent size of 10.7 by 4.4 arcmin, the galaxy is about 120 thousand light years across. (Several IC objects (e.g., IC 3550, 3551, 3552, 3554, 3555, 3563 and 3564) are stars superimposed on NGC 4559, or emission regions within the galaxy.)

For anything else see IC 3592

For anything else see IC 3593.

A part of spiral galaxy NGC 4559, which see for images. For anything else see IC 3550.

The second IC adds "Not found on plate by Schwassmann". (This entry will only contain historical information, for which see Corwin. For anything else see NGC 4526.)

See Corwin about the double listing. Apparent size 1.5 by 1.3 arcmin?

Historical Identification:
Note About Non-Standard Designation: NGC 4562 is sometimes incorrectly referred to as NGC 4565A, and pointlessly so, since it has a perfectly good NGC designation of its own and isn't even particularly close to NGC 4565. Just another example of the stupidity of using non-standard NGC/IC designations.
Physical Information:

Despite a good NGC position, modern blunders resulted in conflation with IC 3556, NGC 4556 and NGC 4536 (see Corwin). Apparent size 0.5 by 0.4 arcmin?

Apparent size 3.5 by 1.5 arcmin? Listed as a member (VCC 1664) of the Virgo Cluster.

Apparent size 15.8 by 2.1 arcmin? NGC 4565 is about 30 million light-years from our Milky Way galaxy. Dust scattered throughout the disk obscures its light, but the nuclear bulge is clearly visible above and below the dust lanes. A little over 100,000 light-years in diameter, NGC4565 is thought to be nearly identical to our own galaxy, and as a result, it is presumed that our galaxy would look very much like this if seen from the same angle.

Warning About Non-Standard Designation: NGC 4562 is one of three galaxies sometimes called "NGC 4565A", "4565B" and "4565C", all of them incorrectly and pointlessly, because each of them has a perfectly good designation of its own, and none of them are particularly close to NGC 4565.) For anything else see NGC 4562.

Warning About Non-Standard Designation: IC 3546 is one of three galaxies sometimes called "NGC 4565A", "4565B" and "4565C", incorrectly and pointlessly, because each of them has a perfectly good designation of its own, and none of them are particularly close to NGC 4565.) For anything else see IC 3546.

Warning About Non-Standard Designation: One of three galaxies sometimes referred to as "NGC 4565A", "4565B" and "4565C", incorrectly and pointlessly, because each of them has a perfectly good designation of its own, and none of them are particularly close to NGC 4565.) For anything else see IC 3543.

Apparent size 1.3 by 0.9 arcmin?

Historical Identification: Per Dreyer, NGC 4567 (= GC 3108 = JH 1358 = JH 1363 = WH IV 8, 1860 RA 12 29 27, NPD 77 58.2) is "very faint, large, north-preceding (northwestern) of double nebula (position angle 160°±)", the other being NGC 4568. The position precesses to RA 12 36 11.8, Dec +11 15 31,about 3.7 arcmin due west of the pair of galaxies listed above, the description fits and there is nothing comparable nearby, so the identification is certain.
Discovery Note: Per Gottlieb, William Herschel's position was poor, so John Herschel recorded the pair as novae (JH 1358 & 1359) at the correct position. However, he also made an observation with a poor position (JH 1363) that "he associated with (WH) IV-8 and IV-9. The error was corrected by d'Arrest (whose notes make it clear that he observed both members of the pair) in an 1863 paper, hence my addition of his name to the discovery credits for both galaxies.
Nickname(s) Note: The pair has long been called the Siamese Twins, but the HST press release calls them the Butterfly Galaxies.
Physical Information: Since this is part of an interacting pair, the best estimate of their distance would be based on the average of their individual distance estimates. Given a recessional velocity relative to the Cosmic Microwave Background of about 2575 km/sec for NGC 4567 and of about 2560 km/sec for NGC 4568, their average recessional velocity of 2565 to 2570 km/sec (and H₀ of 70 km/sec), their Hubble Flow distance is about 120 million light-years, in reasonable agreement with redshift-independent distance estimates of about 55 to 110 million light-years, but twice the 60 million light-year distance quoted in the HST and NOIRLab press releases. There is no reason to believe, based on past mistakes in their press releases, that the HST/NOIRLab distance is better than the Hubble Flow distance, but the pair is thought to be part of the Virgo Cluster (NGC 4567 is VCC 1673, and NGC 4568 is VCC 1676), and if they happen to be near the center of the cluster and headed outward, a substantial portion of their recessional velocity could be due to acceleration caused by their fall into and through the center of the Cluster. Because of that, in the rest of this paragraph I take both the 60 and 120 million light-year distance estimates into account. Given its apparent size of about 3.65 by 2.3 arcmin for the main galaxy and its brighter outline, and about 4.45 by 3.2 arcmin counting the faint partial ring to its west and southwest (from the images below), the main part of NGC 4567 is about 60 to 65 thousand light-years across if it is at the closer distance, and 125 to 130 thousand light-years across if it is at the further distance, and its outer regions span about 75 to 80 thousand light-years if at the closer distance, and about 155 thousand light-years at the further one.

Historical Identification: Per Dreyer, NGC 4568 (= GC 3109 = JH 1359 = JH 1363 = WH IV 9, 1860 RA 12 29 29, NPD 77 59.4) is "very faint, large, south-following (southeastern) of double nebula (position angle 160 °±)," the other being NGC 4567. The position precesses to RA 12 36 13.8, Dec +11 14 19, about 3.6 arcmin due west of the galaxy listed above, but the description fits and there is nothing comparable nearby, so the identification is certain.
Discovery Note: Per Gottlieb, William Herschel's position was poor, so John Herschel recorded the pair as novae (JH 1358 & 1359) at the correct position. However, he also made an observation with a poor position (JH 1363) that "he associated with (WH) IV-8 and IV-9. The error was corrected by d'Arrest (whose notes make it clear that he observed both members of the pair) in an 1863 paper, hence my addition of his name to the discovery credits for both galaxies.
Nickname(s) Note: The pair has long been called the Siamese Twins, but the HST press release calls them the Butterfly Galaxies.
Physical Information: Since NGC 4568 is part of an interacting pair, the best estimate of its (and their) distance is based on an average of their individual data. As shown in detail in the entry for NGC 4567, the pair is either about 120 million light-years away, a little beyond the outer border of the Virgo Cluster (of which they are thought to be members; also see NGC 4567 for that), or 60 million light-years away, near the center of the Cluster but rapidly moving outward as a result of an acceleration caused by their falling from the near border of the Cluster, toward the center and beyond. Because of that, the rest of this paragraph uses both possible distances. Given its apparent size of about 5.1 by 1.75 arcmin (from the images below and following the entry for NGC 4567), NGC 4568 is about 90 thousand light-years across if the pair ia 60 million light-years away, and about 175 to 180 thousand light-years across if it ia 120 million light-years away.

Historical Identification: Per Dreyer, NGC 4569 (= GC 3111, M90, 1860 RA 12 29 46, NPD 76 03.9) is "pretty large, brighter middle and nucleus". The position precesses to RA 12 36 49.8, Dec +3 09 49, essentially dead center on the galaxy listed above and the description fits, so the identification is certain.
Physical Information: The recessional velocity of NGC 4569 is -235 km/sec (in other words, it is approaching us instead of moving away from us, as most galaxies are). Such a velocity normally applies only to objects very close to us, and most early estimates of its distance put it relatively close to or even within the outer reaches of our Local Group. However, it is listed as a member (VCC 1692) of the Virgo Cluster, which is about 60 million light years away, and the reason for its odd radial velocity is probably that the Local Group happens to be moving in the direction of that cluster at about 600 km/sec, so that most of the galaxies in that region have unusually low or even negative recessional velocities. (There is also a large range of motions within massive clusters such as the Virgo Cluster (so-called peculiar velocities, or real motions of the galaxies relative to each other, as opposed to the apparent motion associated with the expansion of the Universe), and even without the motion of the Local Group some of the members of the Virgo Cluster moving toward us relative to the Cluster as a whole would still have small or negative radial velocities.) Even redshift-independent distance estimates, perhaps partly influenced by earlier views concerning its distance, are mostly in the range of 30 to 35 million light years; but as noted above, as a member of the Virgo Cluster, it must be about 60 million light years away, and although the current 'best' guess is just under that, the uncertainty overlaps the rounded off value. This entry therefore adopts 60 million light years as the distance, in which case the galaxy's apparent size of 9.5 by 4.4 arcmin would make it about 165 thousand light years across. NGC 4569 is listed in Arp's Atlas of Peculiar Galaxies, as part of Arp 76. The closeup of the galaxy omits its apparent companion, but the mid-range and wide-field images also show IC 3583.

Apparent size 3.7 by 1.2 arcmin?

Historical Identification: Per Dreyer, NGC 4571 (= GC 3113 = JH 1362 = WH III 602, M 91??, d'Arrest, 1860 RA 12 29 50, NPD 75 01.7) is "very faint, large, extended, very gradually brighter middle, 9th magnitude star near north-following (to the northeast)." The position precesses to RA 12 36 53.2, Dec +14 12 01, only about 1.3 arcmin southwest of the center of the galaxy listed above, and well within its overall outline; the description fits (and the magnitude 8.9 star, BD+15 2483, is exactly where stated) and there is nothing else nearby, so the identification is certain. However, Dreyer's obviously uncertain suggestion that it might be the long-missing M91 (NGC 4548, which see) was definitely wrong (as were several later suppositions about the identity of that object), as NGC 4571 is too faint for Messier to have seen with his small instrument.
Discovery Note: Per Corwin, although the NGC position was good, Schwassmann misidentified the star superimposed on the western side of the galaxy as NGC 4571, and therefore listed the faint object to its left (the core of the actual galaxy) as a "nova", leading to the duplicate (IC2) entry.
Physical Information: NGC 4571's recessional velocity relative to the Cosmic Microwave Background is really too small to be a reasonably certain indicator of its distance, because as a member of the Virgo Cluster (VCC 1696) its "peculiar velocity" (its random motion relative to its neighbors) could be a substantial fraction of its overall velocity, and using its value of about 655 km/sec (and H₀ = 70 km/sec/Mpc) yields a distance of only about 30 million light-years, considerably less than redshift-independent distance estimates of about 40 to 70 million light-years and the HST press release's "approximately 60 million light-years", so the HST estimate is probably a best guess for now (future studies of stars in the galaxy should provide a value deserving greater confidence). Given that and its apparent size of about 3.5 by 3.3 arcmin (from the images below), the galaxy is about 60 to 65 thousand light-years across.
Use By The deVaucouleurs Atlas: NGC 4571 is used by The deVaucouleurs Atlas of Galaxies as an example of type SA(r)c, the (r) referring to the ring around its core. LEDA uses essentially the same classification, while NED uses the slightly less organized classification SA(r)d, but the images shown here make me tend to agree with the deVaucouleurs atlas.

The first IC notes "RA is 12 30 30 (per Bigourdan), which agrees better with William Herschel (12 30 18) than with John". Per Corwin (which see), Bigourdan's position actually refers to a star southeast of the galaxy. Apparent size 1.5 by 0.3 arcmin?

Apparent size 2.5 by 1.9 arcmin?

Apparent size 1.8 by 1.1 arcmin?

Apparent size 2.0 by 1.2 arcmin?

Apparent size 1.2 by 0.8 arcmin? Listed as a member (VCC 1721) of the Virgo Cluster.

Refer to Corwin for the double listing. Apparent size 1.6 by 0.8 arcmin? Listed as a member (VCC 1780) of the Virgo Cluster.

Apparent size 3.1 by 2.3 arcmin? Listed as a member (VCC 1720) of the Virgo Cluster.

Apparent size 6.0 by 4.8 arcmin? Listed as a member (VCC 1727) of the Virgo Cluster.

(Referred to by Corwin in a discussion of the identification of NGC 4577.) Apparent size 2.1 by 1.5 arcmin? Listed as a member (VCC 1730) of the Virgo Cluster.

Apparent size 1.9 by 1.1 arcmin?

Corwin lists this faint fuzzball as an apparent companion of NGC 4581, but it is apparently listed only in NED, and other than its position and magnitude (whence the description line), even that site has nothing to say about the object, so this "entry" may well be pointless.

Refer to Corwin.

Apparent size 1.1 by 0.9 arcmin?

Apparent size 1.4 by 1.0 arcmin? Listed as a member (VCC 1757) of the Virgo Cluster.

Apparent size 0.7 by 0.4 arcmin?

Apparent size 3.8 by 1.2 arcmin? Listed as a member (VCC 1760) of the Virgo Cluster.

Apparent size 1.1 by 0.5 arcmin? Listed as a member (VCC 1763) of the Virgo Cluster.

Apparent size 1.3 by 0.4 arcmin? Listed as a member (VCC 1772) of the Virgo Cluster.

Apparent size 3.4 by 2.8 arcmin?

Apparent size 11 arcmin? Approximately 35 thousand light years away, and 100 light years in diameter.

Refer to Corwin for a discussion of the double listing. Apparent size 1.6 by 0.8 arcmin? Listed as a member (VCC 1780) of the Virgo Cluster.

Apparent size 5.2 by 1.35 arcmin.

Apparent size 3.9 by 2.9 arcmin?

Historical Identification: Per Dreyer, NGC 4594 (= GC 3132 = JH 1376 = WH I 43, 1860 RA 12 32 43, NPD 100 51.2) is "a remarkable object, very bright, very large, extremely extended 92°, very suddenly much bright middle and nucleus". The position precesses to RA 12 39 59.2, Dec -11 37 23, right on the galaxy listed above, so the identification is certain.
Discovery Notes (as M104): Although Méchain discovered this nebula in 1781, his first known correspondence (to Bernoulli) was on May 6, 1783. Méchain probably also communicated with Messier at some earlier date, but it must have been too late for Messier to add it to his Catalog, as his only reference to Méchain's discovery was a handwritten note in his copy of the Connoissance des Temps for 1784. Its prior discovery appears to have been unknown to either of the Herschels or to Dreyer, leading to the lack of any mention of Méchain or Messier in the NGC entry. However, in 1917 Camille Flammarion noted the earlier observations, and given the fact that they were made at essentially the same time Messier finished his Catalog, suggested adding the nebula to Messier's catalog as M104; and it has been treated as such ever since.
Physical Information: Apparent size 8.6 by 4.2 arcmin? (Rather oddly, not listed as a member of the Virgo Cluster in the VCC; redshift-independent distance estimates range from 20 to 65 million light years, with a median of 30 million light years; so perhaps in front of the Cluster, instead of "at its nearer edge" as stated immediately following.) M104 lies at the nearer edge of the 60 million light year distant Virgo cluster of galaxies, and at nearly a trillion solar masses is one of the more massive galaxies in that group, even though relatively small (about 50 thousand light years across). The massive central bulge of the galaxy almost totally obscures the structure of the spiral disk, but a recent reworking of this image, seen on a separate page about M104, reduces the glare from the nucleus, better revealing the spiral structure.

Apparent size 1.7 by 1.1 arcmin? Listed as a member (VCC 1811) of the Virgo Cluster.

Apparent size 4.0 by 3.0 arcmin? Listed as a member (VCC 1813) of the Virgo Cluster.

Apparent size 4.1 by 1.9 arcmin?

Apparent size 1.4 by 1.1 arcmin? Listed as a member (VCC 1827) of the Virgo Cluster.

Apparent size 1.7 by 0.8 arcmin?