Celestial Atlas
(NGC 6500 - 6549) ←     NGC Objects: NGC 6550 - 6599 Link for sharing this page on Facebook     → (NGC 6600 - 6649)
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6567, 6568, 6569, 6570, 6571, 6572, 6573, 6574, 6575, 6576, 6577, 6578, 6579, 6580, 6581, 6582, 6583,
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Page last updated Mar 21, 2017
Added Dreyer NGC entries
WORKING 6574: Adding/updating Steinicke listings/data, checking IDs
WORKING 6553: Add basic pix, tags

NGC 6550 (=
NGC 6549 = PGC 61399)
Discovered (Jul 27, 1864) by Albert Marth (and later listed as NGC 6549)
Discovered (Jul 19, 1882) by Édouard Stephan (and later listed as NGC 6550)
A 14th-magnitude spiral galaxy (type Sbc?) in Hercules (RA 18 05 49.4, Dec +18 32 16)
Historical Identification: Per Dreyer, NGC 6550 (Stephan list XII (#87), 1860 RA 17 59 42, NPD 71 28.4) is "very faint, pretty small, round, several faint stars involved, near m 361", (Marth) 361 being NGC 6549. The second IC adds (erroneously) "6548 = 6550, Swift in Cat. XI.". Considerable confusion has reigned for more than a century as to the correct identification of NGC 6548, 6549, and 6550. NGC 6548 was discovered by William Herschel in 1786. That galaxy and NGC 6549 were observed by Albert Marth in 1864; and in 1880, Edouard Stephan observed three objects in the area -- undoubtedly Herschel and Marth's discoveries, and most likely an asterism which he mistook for a nebula. In compiling the NGC, Dreyer was uncertain which objects were which, and assigned separate numbers for each of the three "discoveries". However, (per Corwin) recent examination of the area makes it fairly certain that NGC 6550 is a mistaken repetition of NGC 6549 (which see for images). As an example of how confused the situation is, NED equates NGC 6548 and 6549, while HyperLeda equates NGC 6548 and 6550; so aside from the fact that both identifications now appear to be wrong, any data which supposedly apply to one NGC object may actually apply to another, and only the PGC listings (or some similar non-NGC identification) should be relied upon.
Physical Information: Given the duplicate entry, see NGC 6549 for anything else.

NGC 6551
Recorded (Jul 7, 1885) by
Francis Leavenworth
A lost object in Sagittarius (RA 18 09 00.0, Dec -29 33 00)
Historical Identification: Per Dreyer, NGC 6551 (Leavenworth list I (#230), 1860 RA 18 00 05, NPD 119 34.1) is "very faint, very small, round, partially resolved (some stars seen)". No object resembling Leavenworth's drawing exists anywhere near his recorded position. Since his drawing looks like a globular cluster, NGC 6551 is usually identified with the nearest globular cluster, NGC 6522 (for instance, the NGC/IC Project lists them as being the same). But aside from a huge error (more than a degree) in position, that object does not really look like his drawing, so even that identification is uncertain at best, and the most accurate description for NGC 6551 would be "lost".

NGC 6552 (= PGC 61252)
Discovered (Oct 6, 1866) by
Heinrich d'Arrest
A 14th-magnitude spiral galaxy (type SBbc?) in Draco (RA 18 00 07.0, Dec +66 36 55)
Historical Identification: Per Dreyer, NGC 6552 (= GC 5893, d'Arrest, 1860 RA 18 00 14, NPD 23 23.7) is "faint, pretty small, irregularly round".
Physical Information: A Seyfert galaxy (type Sy2). Based on a recessional velocity of 7940 km/sec, NGC 6552 is about 370 million light years away. Given that and its apparent size of 1.0 by 0.7? arcmin, it is about 110 thousand light years across. NGC 6552 happens to lie fairly close to NGC 6543, the Cat's Eye Nebula, which is only about 10 arcmin to its west (as shown in the last image, below). However, since NGC 6552 is a distant galaxy, and NGC 6543 is only a few thousand light years away, their juxtaposition is merely coincidental.
DSS image of region near spiral galaxy NGC 6552
Above, a 12 arcmin wide DSS image centered on NGC 6552
Below, a 2.4 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy NGC 6552
Below, a 15 arcmin wide DSS image centered between NGC 6543 and 6552
DSS image of region near spiral galaxy NGC 6552 and planetary nebula NGC 6543, the Cat's Eye Nebula

NGC 6553 (= GCL 88)
Discovered (May 22, 1784) by
William Herschel
Also observed (date?) by John Herschel
An 8th-magnitude globular cluster (type XI) in Sagittarius (RA 18 09 15.6, Dec -25 54 26)
Historical Identification: Per Dreyer, NGC 6553 (= GC 4378 = JH 3730 = WH IV 12, 1860 RA 18 00 44, NPD 115 56.3) is "a globular cluster, faint, large, a little extended, very gradually a little brighter middle, partially resolved (some stars seen), stars from 20th magnitude".
Physical Information: Apparent size 9.2? arcmin.

NGC 6554
Discovered (Jul 14, 1830) by
John Herschel
A group of stars in Sagittarius (RA 18 09 23.0, Dec -18 22 42)
Historical Identification: Per Dreyer, NGC 6554 (= GC 4379 = JH 1995, 1860 RA 18 00 51, NPD 108 26.8) is "a cluster, pretty rich, very little compressed, stars large and small".
Physical Information: Apparent size 20? arcmin.

NGC 6555 (= PGC 61432)
Discovered (Jun 29, 1799) by
William Herschel
Also observed (date?) by Herman Schultz
Also observed (date?) by Guillaume Bigourdan
A 12th-magnitude spiral galaxy (type SBc?) in Hercules (RA 18 07 49.0, Dec +17 36 17)
Historical Identification: Per Dreyer, NGC 6555 (= GC 4383 = WH II 902, Schultz, 1860 RA 18 00 57, NPD 72 24.9) is "faint, large, round, very gradually a little brighter middle". The second IC notes "RA is 18 01 38. Error in RA of Schultz's comparison star. Bigourdan's place agrees".
Physical Information: Apparent size 2.1 by 1.7? arcmin.

NGC 6556
Discovered (Jul 15, 1836) by
John Herschel
Also observed (date?) by Herbert Howe
A group of stars in Sagittarius (RA 18 09 56.0, Dec -27 31 27)
Historical Identification: Per Dreyer, NGC 6556 (= GC 4380 = JH 3732, 1860 RA 18 01 10, NPD 117 32.5) is "faint, very large, considerably extended, a little brighter middle, partially resolved (some stars seen)". The second IC notes (per Howe) "No nebulosity".
Physical Information: Apparent size ? arcmin.

NGC 6557 (= PGC 61770)
Discovered (Jun 30, 1835) by
John Herschel
A 13th-magnitude lenticular galaxy (type S0?) in Octans (RA 18 21 24.7, Dec -76 34 58)
Historical Identification: Per Dreyer, NGC 6557 (= GC 4381 = JH 3728, 1860 RA 18 01 11, NPD 116 36.7) is "very faint, very small, round, gradually a little brighter middle". The first IC adds the correction "NPD is 166 degrees, not 116".
Physical Information: Apparent size 1.6 by 1.1? arcmin.

NGC 6558 (= GCL 89)
Discovered (Aug 3, 1834) by
John Herschel
A 9th-magnitude globular cluster in Sagittarius (RA 18 10 18.4, Dec -31 45 47)
Historical Identification: Per Dreyer, NGC 6558 (= GC 4382 = JH 3731, 1860 RA 18 01 12, NPD 121 46.8) is "a globular cluster, pretty bright, pretty large, round, gradually a little brighter middle, well resolved, clearly consisting of stars, stars from 16th magnitude".
Physical Information: Apparent size 4.2? arcmin.

NGC 6559
Discovered (Jul 1, 1826) by
John Herschel
An emission nebula in Sagittarius (RA 18 09 57.6, Dec -24 06 35)
Historical Identification: Per Dreyer, NGC 6559 (= GC 4384 = JH 1996 = JH 3733, 1860 RA 18 01 24, NPD 114 07.5) is "very faint, very large, a little extended, double star involved".
Physical Information: Apparent size 8 by 5? arcmin.

NGC 6560 (= PGC 61381)
Discovered (Oct 22, 1886) by
Lewis Swift
A 14th-magnitude spiral galaxy (type SBbc?) in Hercules (RA 18 05 13.8, Dec +46 52 54)
Historical Identification: Per Dreyer, NGC 6560 (Swift list V (#84), 1860 RA 18 01 28, NPD 43 07.1) is "most extremely faint, pretty small, irregularly round".
Physical Information: Apparent size 1.2 by 0.8? arcmin.

NGC 6561
Discovered (Jun 27, 1786) by
William Herschel
Also observed (Aug 2, 1826) by John Herschel
Probably a star group in Sagittarius (RA 18 10 30.0, Dec -16 43 30)
Historical Identification: Per Dreyer, NGC 6561 (= GC 4385 = JH 1997 = WH VIII 54, 1860 RA 18 02 25, NPD 106 49.0) is "a cluster, large, a little compressed, stars considerably large" (meaning relatively bright). The position precesses to RA 18 10 31.8, Dec -16 47 41, but there is no obvious cluster in the region. Until recently, though some catalogs listed one position or another for this object, most listed it as nonexistent. However, a 2002 catalog of clusters based on proper motions of stars in various historical catalogs suggests that a group of moderately bright stars centered on the position listed above is probably the otherwise lost NGC 6561. Deciding whether that suggestion is reasonable depends upon interpreting the Herschels' description of the cluster according to their observing conditions. A modern photograph of the region shows a densely crowded stellar field, and seeing any "cluster" is difficult. But adjusting the brightness limits of the image to more closely match those faced by visual observers of two centuries ago, a wide scattering of "considerably large" stars can be seen, centered on a point about 3 arcmin to the north of the NGC position. As a result, it seems more likely than not that the star group more or less centered on the position listed above is what the Herschels observed, and should be listed as NGC 6561.
Physical Information: About 15 by 20 arcmin apparent size. Distance about 11000 ly, making the group about 50 light years across. Based on color excess of supposed members of the group, its age is about 8 million years.
Typical DSS image of region centered on the NGC position for NGC 6561
Above and below, 30 arcmin wide DSS images of the region near NGC 6561. The image above is centered on the NGC position for the cluster, and is shown as usually imaged in such photographic databases. The image below is centered at the position listed in this entry, and is adjusted to better approximate the visual appearance of the region. Comparing the images shows that there is a somewhat extensive but sparsely populated group of relatively bright stars centered just to the north of the NGC position, hence my decision to accept the recent identification as probably correct.
DSS image of region centered on the position listed here for NGC 6561, adjusted to better approximate the region's visual appearance

NGC 6562 (= PGC 61376)
Discovered (Jun 8, 1885) by
Lewis Swift
A 14th-magnitude compact galaxy (type C??) in Draco (RA 18 05 00.8, Dec +56 15 49)
Historical Identification: Per Dreyer, NGC 6562 (Swift list I (#85), 1860 RA 18 02 42, NPD 33 45.2) is "faint, pretty small, round, brighter middle, between 2 stars".
Physical Information: Apparent size 0.7 by 0.7? arcmin.

NGC 6563
Discovered (Sep 3, 1826) by
James Dunlop
Also observed (date?) by John Herschel
An 11th-magnitude planetary nebula in Sagittarius (RA 18 12 02.6, Dec -33 52 04)
Historical Identification: Per Dreyer, NGC 6563 (= GC 4386 = JH 3734, (Dunlop 606), 1860 RA 18 02 48, NPD 123 53.5) is "a planetary nebula, faint, large, considerably extended, hazy border".
Discovery Notes: Neither Dreyer nor Herschel was aware of the possibility that Dunlop observed this object, but it is now thought that it is Dunlop 606, hence the reference in parentheses.
Physical Information: Apparent size 0.8? arcmin.

NGC 6564
Recorded (May 15, 1864) by
Albert Marth
Three stars in Hercules (RA 18 09 02.3, Dec +17 23 40)
Historical Identification: Per Dreyer, NGC 6564 (= GC 5894, Marth #362, 1860 RA 18 02 52, NPD 72 37) is "extremely faint, very small".

NGC 6565
Discovered (Jul 14, 1880) by
Edward Pickering
A 12th-magnitude planetary nebula in Sagittarius (RA 18 11 52.5, Dec -28 10 41)
Historical Identification: Per Dreyer, NGC 6565 (Pickering (HN 42), 1860 RA 18 03 03, NPD 118 12) is "a planetary nebula, stellar".
Physical Information: Apparent size 0.23? arcmin.

NGC 6566 (= PGC 61418)
Discovered (Oct 27, 1861) by
Heinrich d'Arrest
A 15th-magnitude elliptical galaxy (type E0?) in Draco (RA 18 07 00.7, Dec +52 15 38)
Historical Identification: Per Dreyer, NGC 6566 (= GC 4387, d'Arrest, 1860 RA 18 03 51, NPD 37 44.0) is "extremely faint, very small, round, 16th magnitude star near".
Physical Information: Apparent size 0.6 by 0.6? arcmin.

NGC 6567
Discovered (Aug 18, 1882) by
Edward Pickering
An 11th-magnitude planetary nebula in Sagittarius (RA 18 13 45.1, Dec -19 04 32)
Historical Identification: Per Dreyer, NGC 6567 (Pickerig (HN 49), 1860 RA 18 04 02, NPD 109 07) is "a planetary nebula, stellar, 11th magnitude, in a cluster".
Physical Information: Apparent size 0.20? arcmin.

NGC 6568 (= OCL 28)
Discovered (May 26, 1786) by
William Herschel
Also observed (date?) by John Herschel
A 9th-magnitude open cluster (type III1m) in Sagittarius (RA 18 12 44.0, Dec -21 35 00)
Historical Identification: Per Dreyer, NGC 6568 (= GC 4388 = JH 1998 = JH 3735 = WH VII 30, 1860 RA 18 04 21, NPD 111 37.6) is "a cluster, very large, a little compressed".
Physical Information: Apparent size 12? arcmin.

NGC 6569 (= GCL 91)
Discovered (Jul 13, 1784) by
William Herschel
Also observed (date?) by James Dunlop
Also observed (date?) by John Herschel
An 8th-magnitude globular cluster (type VIII) in Sagittarius (RA 18 13 38.9, Dec -31 49 33)
Historical Identification: Per Dreyer, NGC 6569 (= GC 4389 = JH 3736 = WH II 201, Dunlop 619, 1860 RA 18 04 33, NPD 121 51.0) is "a globular cluster, considerably bright, large, round, well resolved, clearly consisting of stars, stars from 15th magnitude".
Physical Information: Apparent size 6.4? arcmin.

NGC 6570 (= PGC 61512)
Discovered (Jun 2, 1864) by
Albert Marth
Also observed (date?) by Heinrich d'Arrest
A 13th-magnitude spiral galaxy (type SBm?) in Ophiuchus (RA 18 11 07.3, Dec +14 05 34)
Historical Identification: Per Dreyer, NGC 6570 (= GC 5895, Marth #363, d'Arrest, 1860 RA 18 04 46, NPD 75 56.4) is "pretty faint, pretty large, round".
Physical Information: Apparent size 1.9 by 1.1? arcmin.

NGC 6571 (= PGC 61504)
Discovered (Jul 27, 1864) by
Albert Marth
A 14th-magnitude lenticular galaxy (type E/S0?) in Hercules (RA 18 10 49.3, Dec +21 14 21)
Historical Identification: Per Dreyer, NGC 6571 (= GC 5896, Marth #364, 1860 RA 18 04 51, NPD 68 48) is "extremely faint, very small, stellar".
Physical Information: Apparent size 0.4 by 0.4? arcmin.

NGC 6572
Discovered (Jul 18, 1825) by
Wilhelm Struve
Also observed (date?) by John Herschel
An 8th-magnitude planetary nebula in Ophiuchus (RA 18 12 06.4, Dec +06 51 15)
Historical Identification: Per Dreyer, NGC 6572 (= GC 4390 = JH 2000, Struve 6, 1860 RA 18 05 18, NPD 83 10.5) is "a planetary nebula, very bright, very small, round, a little hazy".
Physical Information: Apparent size 0.25? arcmin.

NGC 6573
Discovered (Jul 28, 1830) by
John Herschel
A group of stars Sagittarius (RA 18 13 41.5, Dec -22 07 08)
Historical Identification: Per Dreyer, NGC 6573 (= GC 4391 = JH 1999, 1860 RA 18 05 24, NPD 112 10.8) is "a cluster, stars very small" (meaning very faint).
Physical Information: Apparent size 6? arcmin.

NGC 6574 (=
NGC 6610 = PGC 61536)
Discovered (Jul 9, 1863) by Albert Marth (and later listed as NGC 6574)
Discovered (Jul 13, 1876) by Édouard Stephan (and later listed as NGC 6610)
A 12th-magnitude spiral galaxy (type SBbc?) in Hercules (RA 18 11 51.2, Dec +14 58 54)
Historical Identification: Per Dreyer, NGC 6574 (= GC 5897, Marth #365, 1860 RA 18 05 30, NPD 75 03) is "pretty bright, small, round".
Physical Information: Apparent size 1.5 by 1.1? arcmin.

NGC 6575 (= PGC 61506)
Discovered (Jun 7, 1866) by
Truman Safford
Discovered (date?) by Édouard Stephan
A 13th-magnitude elliptical galaxy (type E3?) in Hercules (RA 18 10 57.5, Dec +31 06 58)
Historical Identification: Per Dreyer, NGC 6575 (Stephan list XII (#??), (Safford 33), 1860 RA 18 05 40, NPD 58 54.7) is "pretty bright, small, round"
Discovery Notes: Safford's observations were not published until long after he made them, so Stephan's discovery was independent; and Dreyer did not become aware of them until the NGC was nearly ready for publication, so they are only noted in an appendix and none appear in the individual NGC entries (hence the use of parentheses to show that Safford's observation was not actually in Dreyer's entry).
Physical Information: Apparent size 1.8 by 1.3? arcmin.

NGC 6576 (= PGC 61530)
Discovered (Aug 7, 1864) by
Albert Marth
A 15th-magnitude spiral galaxy (type S??) in Hercules (RA 18 11 47.9, Dec +21 25 44)
Historical Identification: Per Dreyer, NGC 6576 (= GC 5898, Marth #366, 1860 RA 18 05 51, NPD 68 35) is "extremely faint, very small".
Physical Information: Apparent size 0.6 by 0.6? arcmin.

NGC 6577 (= PGC 61543)
Discovered (Aug 7, 1864) by
Albert Marth
A 13th-magnitude elliptical galaxy (type E1?) in Hercules (RA 18 12 01.1, Dec +21 27 50)
Historical Identification: Per Dreyer, NGC 6577 (= GC 5899, Marth #367, 1860 RA 18 06 04, NPD 68 34) is "very faint, small".
Physical Information: Apparent size 1.5 by 1.3? arcmin.

NGC 6578
Discovered (Aug 18, 1882) by
Edward Pickering
A 13th-magnitude planetary nebula in Sagittarius (RA 18 16 16.5, Dec -20 27 00)
Historical Identification: Per Dreyer, NGC 6578 (Pickering (HN 47), 1860 RA 18 06 33, NPD 110 19) is "a planetary nebula, stellar, equal to 13th magnitude star".
Physical Information: A distance estimate (per Palen and Balick) based on HST images at different epochs is 6000 light years, with an uncertainty of about 2000 light years. Given that and an apparent size of 0.18 arcmin, the nebula is about a third of a light year across. The distance estimate is based on a comparison of the expansion rate of the nebula (about 12 miles per second) to its apparent change in size during the interval between the epochs. The accuracy of this technique increases with time, so future efforts should gradually improve our knowledge of the nebula's distance.
DSS image of region near planetary nebula NGC 6578
Above, a 12 arcmin wide DSS image centered on NGC 6578
Below, a 2.4 arcmin wide DSS image of the planetary nebula
DSS image of planetary nebula NGC 6578
Below, an overlay of a ? arcmin wide HST image on the image above (Image Credit Hubble Legacy Archive)
Semi-transparent overlay of an HST image of region near planetary nebula NGC 6578 on a DSS image to show the orientation of the nebula
Below, a ? arcmin wide HST image of the nebula (Image Credit Howard Bond (STScI) and NASA/ESA)
HST image of planetary nebula NGC 6578
Below, a view of the extended halo of NGC 6578 (Image Credit R. Corradi, as posted on the PNIC)
Image by R. Corradi et al of halo surrounding planetary nebula NGC 6578

NGC 6579 (= PGC 61562)
Discovered (Aug 7, 1864) by
Albert Marth
Also observed (date?) by Guillaume Bigourdan
A 14th-magnitude spiral galaxy (type S??) in Hercules (RA 18 12 31.8, Dec +21 25 14)
Historical Identification: Per Dreyer, NGC 6579 (= GC 5900, Marth #368, 1860 RA 18 06 35, NPD 68 36) is "faint, western of double nebula", the other being NGC 6580. The second IC lists a corrected RA (per Bigourdan) of 18 06 23.
Physical Information: Apparent size 0.4 by 0.4? arcmin. 4965 km/sec recessional velocity. An apparent companion of NGC 6580, but the difference in recessional velocity corresponds to a 40 million light year difference in distance, so they are probably an optical double.
DSS image of region near spiral galaxy NGC 6579 and elliptical galaxy NGC 6580
Above, a 12 arcmin wide DSS image centered on NGC 6579 and 6580
Below, a 2.4 arcmin wide DSS image of the pair
DSS image of spiral galaxy NGC 6579 and elliptical galaxy NGC 6580

NGC 6580 (= PGC 61566)
Discovered (Aug 7, 1864) by
Albert Marth
Also observed (date?) by Guillaume Bigourdan
A 13th-magnitude elliptical galaxy (type E5?) in Hercules (RA 18 12 33.7, Dec +21 25 33)
Historical Identification: Per Dreyer, NGC 6580 (= GC 5901, Marth #369, 1860 RA 18 06 37, NPD 68 36) is "faint, eastern of double nebula", the other being NGC 6579. The second IC lists a corrected RA (per Bigourdan) of 18 06 25.
Physical Information: Apparent size 1.3 by 0.7? arcmin. 5843 km/sec recessional velocity. An apparent companion of NGC 6579 (which see for images), but the difference in recessional velocity corresponds to a 40 million light year difference in distance, so they are probably an optical double.

NGC 6581 (=
IC 1280 = PGC 61549)
Discovered (Jul 1, 1870) by Édouard Stephan (and later listed as NGC 6581)
Discovered (Jul 1, 1886) by Guillaume Bigourdan (222) (and later listed as IC 1280)
A 14th-magnitude compact galaxy (type C??) in Hercules (RA 18 12 18.3, Dec +25 39 46)
Historical Identification: Per Dreyer, NGC 6581 (= GC 5902, Stephan list I (#9), 1860 RA 18 06 51, NPD 64 22.8) is "extremely faint, diffuse, between 2 faint stars".
Physical Information: Apparent size 0.4 by 0.4? arcmin.

NGC 6582 (= PGC 61510 + PGC 61513)
Discovered (Jul 24, 1884) by
Lewis Swift
A pair of lenticular galaxies in Hercules
PGC 61510: A 14th-magnitude lenticular galaxy (type E/S0?) at RA 18 11 01.8, Dec +49 54 41
PGC 61513: A 14th-magnitude lenticular galaxy (type E/S0?) at RA 18 11 05.2, Dec +49 54 33
Historical Identification: Per Dreyer, NGC 6582 (Swift list IV (#67), 1860 RA 18 07 23, NPD 40 06.8) is "most extremely faint, pretty small, round".
Physical Information: Apparent size of PGC 61510 = 0.6 by 0.6? arcmin. Apparent size of PGC 61513 = 0.8 by 0.8? arcmin.

NGC 6583 (= OCL 27)
Discovered (May 26, 1786) by
William Herschel
Also observed (date?) by John Herschel
A 10th-magnitude open cluster (type II1m) in Sagittarius (RA 18 15 48.8, Dec -22 08 15)
Historical Identification: Per Dreyer, NGC 6583 (= GC 4392 = JH 2001 = JH 3739 = WH VII 31, 1860 RA 18 07 24, NPD 112 10.4) is "a cluster, pretty rich, pretty compressed, considerably extended, stars from 13th magnitude".
Physical Information: Apparent size 5? arcmin.

NGC 6584 (= GCL 92)
Discovered (Jun 5, 1826) by
James Dunlop
Also observed (date?) by John Herschel
An 8th-magnitude globular cluster (type VIII) in Telescopium (RA 18 18 37.7, Dec -52 12 52)
Historical Identification: Per Dreyer, NGC 6584 (= GC 4393 = JH 3737, Dunlop 376, 1860 RA 18 07 25, NPD 142 15.2) is "a globular cluster, considerably bright, considerably large, round, gradually much brighter middle, well resolved, clearly consisting of stars, stars from 15th magnitude".
Physical Information: Apparent size 6.6? arcmin.

NGC 6585 (= PGC 61553)
Discovered (May 25, 1887) by
Edward Swift
A 13th-magnitude spiral galaxy (type Sbc?) in Hercules (RA 18 12 21.9, Dec +39 38 00)
Historical Identification: Per Dreyer, NGC 6585 (Swift list VI (IX #87), 1860 RA 18 07 34, NPD 50 21.2) is "most extremely faint, small, extremely extended, between several bright stars".
Discovery Notes: This is one of several objects included in a pre-publication version of Swift's list VI sent to Dreyer in 1887 that were inadvertently omitted from the published paper; for most of the objects, including this one, the omission was corrected by including them in Swift's list IX, whence the reference in parentheses.
Physical Information: Apparent size 1.9 by 0.4? arcmin.

NGC 6586 (= PGC 61600)
Discovered (Jul 27, 1864) by
Albert Marth
A 14th-magnitude spiral galaxy (type S??) in Hercules (RA 18 13 38.4, Dec +21 05 27)
Historical Identification: Per Dreyer, NGC 6586 (= GC 5903, Marth #370, 1860 RA 18 07 38, NPD 68 57) is "extremely faint, small, round".
Physical Information: Apparent size 0.9 by 0.5? arcmin.

NGC 6587 (= PGC 61607)
Discovered (Jul 31, 1864) by
Albert Marth
A 13th-magnitude lenticular galaxy (type E/SB0?) in Hercules (RA 18 13 50.8, Dec +18 49 33)
Historical Identification: Per Dreyer, NGC 6587 (= GC 5904, Marth #371, 1860 RA 18 07 43, NPD 71 13) is "faint, very small, round, stellar".
Physical Information: Apparent size 1.3 by 1.1? arcmin.

NGC 6588
Discovered (Jun 8, 1836) by
John Herschel
Also observed by DeLisle Stewart
A chain of about 20 stars in Pavo (RA 18 21 27.0, Dec -63 48 24)
Historical Identification: Per Dreyer, NGC 6588 (= GC 4394 = JH 3738, 1860 RA 18 07 57, NPD 153 51.3) is "extremely faint, small, 6th magnitude star to southwest". The second IC notes (per DeLisle Stewart) "Not seen, several very faint stars, no nebulosity".
Physical Information:

NGC 6589 (=
IC 4690)
Discovered (Aug 28, 1867) by Truman Safford (and later listed as NGC 6589)
Discovered (date?) by Lewis Swift (and later listed as NGC 6589)
Also observed (date?) by Edward Barnard (while listed as NGC 6589)
Discovered (August, 1905) by Edward Barnard (and later listed as IC 4690)
A reflection nebula in Sagittarius (RA 18 16 51.7, Dec -19 46 41)
Historical Identification: Per Dreyer, NGC 6589 (Swift list II (#??), (Safford 81), 1860 RA 18 07 59, NPD 109 50.3) is "a double star in center of extremely faint, pretty large nebulosity". The first IC adds "Place is RA 18 08 35, NPD 109 48.9, and 6590 = 6595 (Barnard, A.N. 3101)".
Discovery Notes: Safford's observations were not published until long after they were made, so Swift's discovery was independent; and since Dreyer's NGC was nearly ready for publication when he became aware of them, he only noted them in an appendix and none were included in individual NGC entries (hence the use of parentheses in the entry shown here).
Physical Information: Apparent size 5.0 by 3.0? arcmin.

NGC 6590 (=
NGC 6595 = IC 4700 = OCL 31)
Discovered (Jul 14, 1830) by John Herschel (and later listed as NGC 6595)
Discovered (Jul 12, 1885) by Lewis Swift (and later listed as NGC 6590)
Also observed (date?) by Edward Barnard (while listed as NGC 6590 and 6595)
Discovered (August, 1905) by Edward Barnard (and later listed as IC 4700)
An emission nebula and open cluster in Sagittarius (RA 18 17 04.8, Dec -19 51 58)
Historical Identification: Per Dreyer, NGC 6590 (Swift list II (#62), 1860 RA 18 08 01, NPD 109 55.3) is "a double star in center of pretty faint, pretty large, round nebulosity". The first IC adds (in a comment about 6589) "Place is RA 18 08 35, NPD 109 48.9, and 6590 = 6595 (Barnard, A.N. 3101)".
Physical Information: Apparent size 11? arcmin.

NGC 6591 (= PGC 61610)
Discovered (Jul 27, 1864) by
Albert Marth
A 16th-magnitude spiral galaxy (type S??) in Hercules (RA 18 14 03.7, Dec +21 03 49)
Historical Identification: Per Dreyer, NGC 6591 (= GC 5905, Marth #372, 1860 RA 18 08 02, NPD 68 59) is "most extremely faint, very small, stellar".
Physical Information: Apparent size 0.3 by 0.1? arcmin.

NGC 6592 (= PGC 61477)
Discovered (Jun 14, 1885) by
Lewis Swift
A 14th-magnitude lenticular galaxy (type E/S0?) in Draco (RA 18 09 50.6, Dec +61 25 21)
Historical Identification: Per Dreyer, NGC 6592 (Swift list I (#86), 1860 RA 18 08 10, NPD 28 36.3) is "very faint, very small, round".
Physical Information: Apparent size 0.5 by 0.4? arcmin.

NGC 6593 (= PGC 61617)
Discovered (Jun 10, 1864) by
Albert Marth
Also observed (date?) by Édouard Stephan
A 14th-magnitude lenticular galaxy (type E/S0?) in Hercules (RA 18 14 03.6, Dec +22 17 05)
Historical Identification: Per Dreyer, NGC 6593 (= GC 5906, Marth #373, Stephan list VII (#??), 1860 RA 18 08 10, NPD 67 45.2) is "very faint, very small, round, a little brighter middle".
Physical Information: Apparent size 0.8 by 0.4? arcmin.

NGC 6594 (= PGC 61482)
Discovered (Jun 14, 1885) by
Lewis Swift
A 15th-magnitude spiral galaxy (type S??) in Draco (RA 18 10 05.6, Dec +61 08 01)
Historical Identification: Per Dreyer, NGC 6594 (Swift list I (#87), 1860 RA 18 08 34, NPD 28 53.6) is "very faint, very small, round".
Physical Information: Apparent size 1.0 by 0.7? arcmin.

NGC 6595 (=
NGC 6590 = IC 4700 = OCL 31)
Discovered (Jul 14, 1830) by John Herschel (and later listed as NGC 6595)
Discovered (Jul 12, 1885) by Lewis Swift (and later listed as NGC 6590)
Also observed (date?) by Edward Barnard (while listed as NGC 6590 and 6595)
Discovered (August, 1905) by Edward Barnard (and later listed as IC 4700)
An emission nebula and open cluster in Sagittarius (RA 18 17 04.8, Dec -19 51 58)
Historical Identification: Per Dreyer, NGC 6595 (= GC 4395 = JH 2002, 1860 RA 18 08 47, NPD 109 55.1) is "faint, pretty large, considerably extended, double star involved". The first IC adds (in a comment about 6589) "Place is RA 18 08 35, NPD 109 48.9, and 6590 = 6595 (Barnard, A.N. 3101)".
Physical Information: Given the duplicate entry, see NGC 6590 for anything else.

NGC 6596 (= OCL 41)
Discovered (Jun 27, 1786) by
William Herschel
Also observed (date?) by John Herschel
An open cluster (type III2m) in Sagittarius (RA 18 17 33.0, Dec -16 39 00)
Historical Identification: Per Dreyer, NGC 6596 (= GC 4396 = JH 2003 = WH VIII 55, 1860 RA 18 09 28, NPD 106 41.4) is "a cluster, a little compressed".
Physical Information: Apparent size 10? arcmin.

NGC 6597 (= PGC 61520)
Discovered (Jun 14, 1885) by
Lewis Swift
A 15th-magnitude elliptical galaxy (type E5?) in Draco (RA 18 11 13.4, Dec +61 10 52)
Historical Identification: Per Dreyer, NGC 6597 (Swift list I (#89), 1860 RA 18 09 34, NPD 28 51.1) is "very faint, very small, round, bright star near".
Physical Information: Apparent size 0.8 by 0.4? arcmin.

NGC 6598 (= PGC 61462)
Discovered (Sep 6, 1883) by
Lewis Swift
A 13th-magnitude spiral galaxy (type S?? pec) in Draco (RA 18 08 55.7, Dec +69 04 07)
Historical Identification: Per Dreyer, NGC 6598 (Swift list I (#88), 1860 RA 18 09 50, NPD 20 58.6) is "extremely faint, pretty small, round". The position precesses to RA 18 08 52.2, Dec +69 03 19, just over an arcmin to the southwest of the galaxy; given the galaxy's size and proximity and the lack of any other nearby objects, the identification is certain.
Physical Information: Based on a recessional velocity of 8310 km/sec, NGC 6598 is about 390 million light years away. Given that and its apparent size of 2.0 by 1.4 arcmin, it is about 225 thousand light years across.
DSS image of region near spiral galaxy NGC 6598
Above, a 12 arcmin wide DSS image centered on NGC 6598
Below, a 2.4 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy NGC 6598

NGC 6599 (=
NGC 6600 = PGC 61655)
Discovered (Jun 6, 1864) by Albert Marth (and later listed as NGC 6600)
Discovered (Jul 27, 1880) by Édouard Stephan (and later listed as NGC 6599)
A 13th-magnitude lenticular galaxy (type S0?) in Hercules (RA 18 15 42.9, Dec +24 54 47)
Historical Identification: Per Dreyer, NGC 6599 (Stephan list XII (#89), 1860 RA 18 09 59, NPD 65 07.8) is "pretty faint, very small, round, gradually brighter middle, small star attached on east".
Physical Information: Apparent size 1.3 by 1.2? arcmin
Celestial Atlas
(NGC 6500 - 6549) ←     NGC Objects: NGC 6550 - 6599     → (NGC 6600 - 6649)