QuickLinks: 4700, 4701, 4702, 4703, 4704, 4705, 4706, 4707, 4708, 4709, 4710, 4711, 4712, 4713, 4714, 4715, 4716, 4717, 4718, 4719, 4720, 4721, 4722, 4723, 4724, 4725, 4726, 4727, 4728, 4729, 4730, 4731, 4732, 4733, 4734, 4735, 4736, 4737, 4738, 4739, 4740, 4741, 4742, 4743, 4744, 4745, 4746, 4747, 4748, 4749
Page last updated Jun 30, 2011
WORKING: Add positions/physical data (per Steinicke)
WORKING: Add/update discoverers (per Steinicke)
WORKING: Check existing pix for size, quality
IC 4700 (= NGC 6590= NGC 6595)
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)
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)
(Positions may have been erroneous, or refer to different parts of the same object; will deal with that later)
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IC 4701
IC 4702
IC 4703 -- The Eagle Nebula Discovered (1876) by Etienne Trouvelot Listed by Dreyer as discovered (1894) by Isaac Roberts An emission nebula associated with a star cluster (NGC 6611) in Serpens (RA 18 18 56, Dec -13 50 43)
Dreyer's position precesses to an area near the boundary of the nebula, so the identification is certain, but the discoverer is wrong. Although Roberts photographed the nebula in 1894, it had already been visually observed and described in detail by Trouvelot, who suggested a name (the Fan) which seems more appropriate than its more commonly used name (of unknown origin). (Wolfgang Steinicke's upcoming book on the NGC and IC catalogs is the source of this information, and anyone interested in the history of those catalogs should consider purchasing a copy.) The Eagle Nebula and the young star cluster associated with it are about 7000 light years away, meaning we see them as they were 7000 years ago. But to the left of the brightest part of the nebula, where the star cluster is centered, is a violently expanding cloud of gas caused by a supernova which took place a few thousand years beforehand. Estimates are that six thousand years ago, high-velocity supernova gases slammed into, compressed and simultaneously tore apart the so-called "Pillars of Creation" near the center of the nebula (though we won't see that until a millennium from now). In the process, most of the clouds of gas and dust visible here would be torn apart, but some of the denser nodules hidden inside the Pillars would be violently compressed, to quickly form bright new stars. In fact, in such regions, close to half the bright stars formed are the result of such events, and for lower mass stars like our Sun, compression by expanding gases is almost always the cause of their formation. |
 Above, NOAO image of the entire nebula (click here for a much larger view of this image) (T.A.Rector (NRAO/AUI/NSF and NOAO/AURA/NSF) and B.A.Wolpa (AURA/NSF), NOAO) Below, a closer (cropped) view of the image above At the very bottom (for now), a Hubble Space Telescope view of the "Pillars of Creation"

 (J. Hester, P. Scowen (ASU), HST, NASA, apod070218)
IC 4704
IC 4705
IC 4706
IC 4707
IC 4708
IC 4709
IC 4710
IC 4711
IC 4712
IC 4713
IC 4714
IC 4715 (= M24) Discovered (1764) by Charles Messier Star clouds in Sagittarius (RA 18 18 48, Dec -18 33 00) (Image Credit: Fred Calvert & Adam Block, NOAO, AURA, NSF, apod040921)

IC 4716
IC 4717
IC 4718
IC 4719
IC 4720
IC 4721
IC 4722
IC 4723
IC 4724
IC 4725 (= M25) Discovered (1764) by Philippe de Cheseaux Also discovered (1764) by Charles Messier A 5th-magnitude open cluster in Sagittarius (RA 18 31 45, Dec -19 07 12)
(J-C. Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight, apod090831; Copyright CFHT)

IC 4726
IC 4727
IC 4728
IC 4729
IC 4730
IC 4731
IC 4732
IC 4733
IC 4734
IC 4735
IC 4736
IC 4737
IC 4738
IC 4739
IC 4740
IC 4741
IC 4742
IC 4743
IC 4744
IC 4745
IC 4746
IC 4747
IC 4748
IC 4749
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