Celestial Atlas
(IC 4900 - 4949) ←IC Objects: IC 4950 - 4999→ (IC 5000 - 5049)
Click here for Introductory Material
QuickLinks:
4950, 4951, 4952, 4953, 4954, 4955, 4956, 4957, 4958, 4959, 4960, 4961, 4962, 4963, 4964, 4965, 4966,
4967, 4968, 4969, 4970, 4971, 4972, 4973, 4974, 4975, 4976, 4977, 4978, 4979, 4980, 4981, 4982, 4983,
4984, 4985, 4986, 4987, 4988, 4989, 4990, 4991, 4992, 4993, 4994, 4995, 4996, 4997, 4998, 4999

Page last updated May 18, 2020
WORKING: Add physical information

IC 4950 (= PGC 64159)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 14.4 spiral galaxy (type SAB(rs)b?) in Telescopium (RA 20 08 27.4, Dec -56 09 42)
Historical Identification: Per Dreyer, IC 4950 (= DeLisle Stewart #642, 1860 RA 19 57 11, NPD 146 34) is "extremely faint, very small, extremely extended 35°, a little brighter middle". The position precesses to RA 20 08 23.2, Dec -56 10 07, about 0.7 arcmin southwest of the galaxy listed above (and not far from its southwestern end), the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 4330 km/sec, IC 4950 is about 200 million light years away, in good agreement with redshift-independent distance estimates of 165 to 195 million light years. Given that and its apparent size of 1.35 by 0.4 arcmin, it is about 80 thousand light years across.
DSS image of region near spiral galaxy IC 4950
Above, a 12 arcmin wide DSS image centered on IC 4950
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4950

IC 4951 (= PGC 64181)
Discovered (Aug 15, 1901) by
DeLisle Stewart
A magnitude 13.3 spiral galaxy (type SB(s)dm?) in Pavo (RA 20 09 31.7, Dec -61 50 58)
Historical Identification: Per Dreyer, IC 4951 (= DeLisle Stewart #645, 1860 RA 19 57 11, NPD 152 16) is "very faint, very small, extremely extended 170°, very much brighter middle". The position precesses to RA 20 09 24.3, Dec -61 52 02, about 1.4 arcmin southwest of the galaxy listed above (due west of its southern end), the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 2.85 by 0.5 arcmin.
DSS image of region near spiral galaxy IC 4951
Above, a 12 arcmin wide DSS image centered on IC 4951
Below, a 3.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4951

IC 4952 (= PGC 64163)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 13.1 spiral galaxy (type Sa?) in Telescopium (RA 20 08 37.6, Dec -55 27 12)
Historical Identification: Per Dreyer, IC 4952 (= DeLisle Stewart #644, 1860 RA 19 57 31, NPD 145 51) is "faint, very small, considerably extended 10°". The position precesses to RA 20 08 36.6, Dec -55 27 04, on the western rim of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.15 by 0.55 arcmin.
DSS image of region near spiral galaxy IC 4952
Above, a 12 arcmin wide DSS image centered on IC 4952
Below, a 1.4 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4952

IC 4953 (= PGC 64193)
Discovered (September 1901) by
DeLisle Stewart
A magnitude 14.9 spiral galaxy (type Sc pec?) in Pavo (RA 20 09 59.8, Dec -62 47 32)
Historical Identification: Per Dreyer, IC 4953 (= DeLisle Stewart #646, 1860 RA 19 57 38, NPD 153 12) is "extremely faint, extremely small, considerably extended 60°, between 2 extremely faint stars". The position precesses to RA 20 10 03.2, Dec -62 47 56, only half an arcmin southeast of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 9265 km/sec, a straightforward calculation indicates that IC 4953 is about 430 million light years away. 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 415 million light years away at the time the light by which we see it was emitted, a little over 420 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 0.6 by 0.35 arcmin, the galaxy is about 70 thousand light years across.
DSS image of region near spiral galaxy IC 4953
Above, a 12 arcmin wide DSS image centered on IC 4953
Below, a 0.75 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4953

IC 4954 (= part of LBN 153)
Discovered by
Edward Barnard
A reflection nebula in Vulpecula (RA 20 04 44.8, Dec +29 15 12)
Historical Identification: Per Dreyer, IC 4954 (= Barnard, 1860 RA 19 59 06, NPD 61 08.7) is a "double nebulous star, irregular figure, 11th magnitude star close". The position precesses to RA 20 04 46.7, Dec +29 15 02, only 0.4 arcmin southeast of the double star at the center of the reflection nebula listed above, and the description fits so the identification is certain.
Physical Information: IC 4954 is part of a nebulous star-forming region including IC 4955 and other reflection nebulae. It is thought to be about 6 to 8 thousand light years away. Given that and its apparent size of about 1.0 by 0.7 arcmin, the reflection nebula is about two light years across. The sharp edge of some of the reflection nebulae is caused by ionized gases being blown away from very hot stars within the cluster that lights up the region. Such sharp structures cannot last for more than a few million years, and based on that the cluster is thought to have begun to form about 4 million years ago.
NOAO image of region near reflection nebula IC 4954, superimposed on a DSS background to fill in missing areas; also shown is IC 4955
Above, a 12 arcmin wide image centered on IC 4954, also showing IC 4955
(Image Credits above and below Adam Block/NOAO/AURA/NSF; image above superimposed on DSS background)
Below, a 6 arcmin wide image centered between IC 4954 and 4955
NOAO image of region near reflection nebulae IC 4954 and IC 4955
Below, a 2.0 arcmin wide image of the reflection nebula (Image credits as above)
NOAO image of reflection nebula IC 4954

IC 4955 (= part of LBN 153)
Discovered by
Edward Barnard
A reflection nebula in Vulpecula (RA 20 04 52.5, Dec +29 11 28)
Historical Identification: Per Dreyer, IC 4955 (= Barnard, 1860 RA 19 59 12, NPD 61 12.3) is a "fine nebulous 12th magnitude star". The position precesses to RA 20 04 53.0, Dec +29 11 27, less than 0.2 arcmin southeast of the star associated with the reflection nebula listed above, so the identification is certain.
Physical Information: IC 4955 is part of a nebulous region including IC 4954 (which see for a further discussion of the region) and other reflection nebulae. The region is thought to be about 6 to 8 thousand light years away. Given that and its apparent size of about 1.5 by 0.9 arcmin, IC 4955 is about three light years across.
NOAO image of region near reflection nebula IC 4955, superimposed on a DSS background to fill in missing areas; also shown is IC 4954
Above, a 12 arcmin wide image centered on IC 4955, also showing IC 4954
(Image Credits above and below Adam Block/NOAO/AURA/NSF; image above superimposed on DSS background)
Below, a 6 arcmin wide image centered between IC 4955 and 4954
NOAO image of region near reflection nebulae IC 4954 and IC 4955
Below, a 2.0 arcmin wide image of the reflection nebula (Image credits as above)
NOAO image of reflection nebula IC 4955

IC 4956 (probably = PGC 64230)
Discovered (Jul 22, 1897) by
Lewis Swift
Probably a magnitude 12.4 elliptical galaxy (type E0?) in Telescopium (RA 20 11 31.3, Dec -45 35 36)
Historical Identification: Per Dreyer, IC 4956 (= Swift list XI (#190), 1860 RA 19 59 25, NPD 136 02.5) is "very faint, pretty small, round". The position precesses to RA 20 09 20.3, Dec -45 38 21, but there is nothing there. However, the galaxy listed above lies just over 2 minutes of time to the east (not an unusual error for Swift), and since it fits the description and there is nothing else nearby it is generally thought to be what Swift saw, and although not certain the identification does seem reasonable.
Physical Information: Apparent size 1.9 by 1.9 arcmin.
DSS image of region near elliptical galaxy IC 4956
Above, a 12 arcmin wide DSS image centered on IC 4956
Below, a 2.4 arcmin wide DSS image of the galaxy
DSS image of elliptical galaxy IC 4956
Below, a closeup of the core of the galaxy (Image Credit Hubble Legacy Archive, post-processing Courtney Seligman)
HST image of core of ellilptical galaxy IC 4956

IC 4957 (= PGC 64183)
Discovered (May 17, 1904) by
Royal Frost
A magnitude 14.5 spiral galaxy (type (R')SB(s)ab?) in Telescopium (RA 20 09 35.5, Dec -55 42 33)
Historical Identification: Per Dreyer, IC 4957 (= Frost #1188, 1860 RA 19 59 36, NPD 146 06) has a "brighter middle, magnitude 14". The position precesses to RA 20 10 42.4, Dec -55 41 42, but there is nothing that matches the description at that position. However, there is a suitable candidate about a minute of time to the west, suggesting a single-digit error in Frost's right ascension. Applying a correction for the presumed error yields a position of RA 20 09 43.4, Dec -55 41 34, less than 1.5 arcmin northeast of the galaxy listed above, so the identification seems reasonably certain.
Physical Information: Apparent size 1.0 by 0.55 arcmin.
DSS image of region near spiral galaxy IC 4957
Above, a 12 arcmin wide DSS image centered on IC 4957
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4957

IC 4958 (= PGC 64370)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 15.2 spiral galaxy (type Sc?) in Pavo (RA 20 15 35.0, Dec -72 42 41)
Historical Identification: Per Dreyer, IC 4958 (= DeLisle Stewart #649, 1860 RA 19 59 44, NPD 163 07) is "extremely faint, brighter middle". The position precesses to RA 20 15 31.0, Dec -72 42 16, only 0.5 arcmin northwest of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.45 by 0.35 arcmin.
DSS image of region near spiral galaxy IC 4958
Above, a 12 arcmin wide DSS image centered on IC 4958
Below, a 0.6 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4958

IC 4959
Recorded (1899) by
DeLisle Stewart
Probably a nonexistent object in Telescopium (RA 20 10 57.5, Dec -53 05 38)
though possibly a poor observation of IC 4961
Historical Identification: Per Dreyer, IC 4959 (= DeLisle Stewart #647, 1860 RA 20 00 13, NPD 143 30) is a "hazy star". The position precesses to RA 20 10 57.5, Dec -53 05 38 (whence the position listed above), but barring an unusually large positional error by Stewart, there is nothing there. Corwin suspects that IC 4959 probably represents a plate defect, in which case it is a nonexistent object, but notes that on the one-hour Bruce plate taken by Stewart IC 4961 (a diffuse galaxy 5 arcmin east southeast of Stewart's position) might have looked like a hazy star, so although he thinks it unlikely, he suggests that it might be a poorly recorded observation of that object. But whether IC 4959 represents a plate defect or a duplicate entry, it is not an otherwise uncataloged object, and its entry is of interest only for historical reasons.
DSS image of region near the apparently nonexistent IC 4959
Above, a 12 arcmin wide DSS image centered on the IC2 position for IC 4959, also showing IC 4961

IC 4960 (= PGC 64363)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.4 lenticular galaxy (type SAB0(s)a?) in Pavo (RA 20 15 23.8, Dec -70 32 14)
Historical Identification: Per Dreyer, IC 4960 (= DeLisle Stewart #651, 1860 RA 20 00 32, NPD 160 57) is "extremely faint, extremely small, brighter middle". The position precesses to RA 20 15 16.6, Dec -70 32 13, only 0.6 arcemin west of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.1 by 0.45 arcmin.
DSS image of region near lenticular galaxy IC 4960, also showing IC 4967
Above, a 12 arcmin wide DSS image centered on IC 4960, also showing IC 4967
Below, a 1.4 arcmin wide DSS image of the galaxy
DSS image of lenticular galaxy IC 4960

IC 4961 (= PGC 64229)
Possibly recorded (1899) by
DeLisle Stewart
Discovered (Aug 31, 1904) by Royal Frost
A magnitude 14.2 spiral galaxy (type SAB(s)dm?) in Telescopium (RA 20 11 28.6, Dec -53 07 30)
Historical Identification: Per Dreyer, IC 4961 (= Frost #1189, 1860 RA 20 00 37, NPD 143 33) is "faint, pretty small, much extended 90°, diffuse". The position precesses to RA 20 11 21.7, Dec -53 08 34, only about 1.5 arcmin southwest of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain. (See IC 4959 about the remote possibility that Stewart might have observed IC 4961.)
Physical Information: Apparent size 1.45 by 0.4 arcmin.
DSS image of region near spiral galaxy IC 4961
Above, a 12 arcmin wide DSS image centered on IC 4961
Below, a 1.6 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4961

IC 4962 (probably = PGC 3920415)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 16(?) elliptical galaxy (type E3?) in Pavo (RA 20 15 54.3, Dec -70 59 48)
Historical Identification: Per Dreyer, IC 4962 (= DeLisle Stewart #652, 1860 RA 20 01 01, NPD 161 25) is "faint, small, extremely extended 160°, very much brighter middle". The position precesses to RA 20 15 57.0, Dec -71 00 07, less than 0.4 arcmin southeast of the galaxy listed above. It fits the description fairly well and there is nothing else nearby, so the identification seems reasonably certain, but almost every reference save Thomson (mis?)identifies PGC 64402 as IC 4962. The latter galaxy does fit the description better, but its more than 8 arcmin positional error would be unusual for Stewart, and its lower surface brightness would have made it a more difficult object for him to observe. It therefore seems more likely that PGC 3920415 is the actual IC 4962, but it is possible that the generally accepted identification is correct, for which reason see the entry immediately below.
Physical Information: Apparent size 0.35 by 0.25 arcmin.
DSS image of region near elliptical galaxy PGC 3920415, which is probably IC 4962
Above, a 12 arcmin wide DSS image centered on PGC 3920415, which is probably IC 4962
Below, a 0.6 arcmin wide DSS image of the galaxy
DSS image of elliptical galaxy PGC 3920415, which is probably IC 4962

PGC 64402 (perhaps =
IC 4962)
Probably not an IC object but listed here since usually (mis?)identified as IC 4962
A magnitude 15.4 spiral galaxy (type Sc?) in Pavo (RA 20 16 42.1, Dec -71 07 50)
Historical Identification: See IC 4962 for a discussion of the possibility that PGC 64402 corresponds to that IC entry.
Physical Information: Apparent size 0.85 by 0.2 arcmin.
DSS image of region near spiral galaxy PGC 64402, which is usually (mis?)identified as IC 4962
Above, a 12 arcmin wide DSS image centered on PGC 64402
Below, a 1.0 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy PGC 64402, which is usually (mis?)identified as IC 4962

IC 4963 (= PGC 64255)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 13.3 spiral galaxy (type (R')SAB(rs)a pec?) in Telescopium (RA 20 12 05.5, Dec -55 14 44)
Historical Identification: Per Dreyer, IC 4963 (= DeLisle Stewart #648, 1860 RA 20 01 02, NPD 145 39) is "very faint, very small, round". The position precesses to RA 20 12 03.6, Dec -55 14 28, on the northwest rim of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 2.5 by 0.55 arcmin.
DSS image of region near spiral galaxy IC 4963
Above, a 12 arcmin wide DSS image centered on IC 4963
Below, a 2.8 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4963

IC 4964 (= PGC 64432)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.8 spiral galaxy (type SA(s)cd?) in Pavo (RA 20 17 23.9, Dec -73 53 07)
Historical Identification: Per Dreyer, IC 4964 (= DeLisle Stewart #654, 1860 RA 20 01 02, NPD 164 18) is "faint, small, considerably brighter middle". The position precesses to RA 20 17 27.2, Dec -73 53 00, on the eastern rim of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.4 by 0.6 arcmin.
DSS image of region near spiral galaxy IC 4964
Above, a 12 arcmin wide DSS image centered on IC 4964
Below, a 1.6 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4964

IC 4965 (= PGC 64272)
Discovered (May 17, 1904) by
Royal Frost
A magnitude 13.7 lenticular galaxy (type SA0?) in Pavo (RA 20 12 27.3, Dec -56 49 36)
Historical Identification: Per Dreyer, IC 4965 (= Frost #1190, 1860 RA 20 01 04, NPD 147 15) has a "brighter middle, magnitude 15". The position precesses to RA 20 12 19.9, Dec -56 50 26, about 1.3 arcmin southwest of the galaxy listed above and there is nothing of comparable brightness nearby, so the identification is reasonably certain.
Physical Information: Based on a recessional velocity of 16690 km/sec, a straightforward calculation indicates that IC 4953 is about 775 million light years away. 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 730 million light years away at the time the light by which we see it was emitted, about 750 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 1.35 by 0.95 arcmin, the galaxy is about 285 thousand light years across.
DSS image of region near lenticular galaxy IC 4965
Above, a 12 arcmin wide DSS image centered on IC 4965
Below, a 1.8 arcmin wide DSS image of the galaxy
DSS image of lenticular galaxy IC 4965

IC 4966
Recorded (1899) by
DeLisle Stewart
A line of three stars in Telescopium (RA 20 12 16.4, Dec -53 37 11)
Historical Identification: Per Dreyer, IC 4966 (= DeLisle Stewart #650, 1860 RA 20 01 30, NPD 144 01) is "faint, very small, extended 40°". Stewart's position precesses to RA 20 12 17.8, Dec -53 36 14, just under an arcmin north of the line of stars listed above, which perfectly fits the description and could easily appear to be a nebula object on the one-hour plate examined by Stewart, so the identification is reasonably certain. However, several references list PGC 64297 as IC 4966, so though that is almost certainly wrong, the object is discussed in the entry immediately below.
Physical Information: The three stars form a line about 0.35 arcmin long.
DSS image of region near the line of three stars that comprises IC 4966
Above, a 12 arcmin wide DSS image centered on IC 4966
Below, a 20 arcmin wide DSS image centered on IC 4966, also showing PGC 64297
DSS image of region near the line of three stars that comprises IC 4966, also showing PGC 64297, which is sometimes misidentified as IC 4966

PGC 64297 (not =
IC 4966)
Not an IC object but listed here since sometimes misidentified as IC 4966
A magnitude 15.5(?) spiral galaxy (type Sbc?) in Telescopium (RA 20 13 14.2, Dec -53 29 58)
Historical Identification: As noted in the entry for IC 4966, PGC 64297 is sometimes misidentified as that IC object. However, (per Corwin) the galaxy does not fit Stewart's description of his #650, and its positional error is both large and unlikely, being well off in both right ascension and declination. As a result, it is virtually certain that it is not IC 4966.
Physical Information: Apparent size 0.75 by 0.3 arcmin.
DSS image of region near spiral galaxy PGC 64297, which is sometimes misidentified as IC 4966
Above, a 12 arcmin wide DSS image centered on PGC 64297
Below, a 0.8 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy PGC 64297, which is sometimes misidentified as IC 4966

IC 4967 (= PGC 64396)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.8 elliptical galaxy (type E1?) in Pavo (RA 20 16 23.0, Dec -70 33 51)
Historical Identification: Per Dreyer, IC 4967 (= DeLisle Stewart #655, 1860 RA 20 01 38, NPD 160 59) is "very faint, brighter middle". The position precesses to RA 20 16 22.1, Dec -70 34 02, right on the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.7 by 0.65 arcmin.
DSS image of region near elliptical galaxy IC 4967, also showing IC 4960 and IC 4971
Above, a 12 arcmin wide DSS image centered on IC 4967, also showing IC 4960 and IC 4971
Below, a 1.0 arcmin wide DSS image of the galaxy
DSS image of elliptical galaxy IC 4967

IC 4968 (= PGC 64345)
Discovered (Aug 15, 1901) by
DeLisle Stewart
A magnitude 14.2 spiral galaxy (type (R)SB(rs)ab?) in Pavo (RA 20 14 50.0, Dec -64 47 54)
Historical Identification: Per Dreyer, IC 4968 (= DeLisle Stewart #653, 1860 RA 20 01 48, NPD 155 12) is "very faint, small, bright star 3 arcmin to southeast". The position precesses to RA 20 14 38.3, Dec -64 47 10, almost 1.5 arcmin northwest of the galaxy listed above, but there is nothing else nearby, and the 7th magnitude star to the east southeast makes the identification certain.
Physical Information: Apparent size 0.7 by 0.55 arcmin.
DSS image of region near spiral galaxy IC 4968
Above, a 12 arcmin wide DSS image centered on IC 4968
Below, a 0.9 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4968

IC 4969 (= PGC 64288)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 14.2 spiral galaxy (type (R')SA(rs)a pec?) in Telescopium (RA 20 12 56.3, Dec -53 55 12)
Historical Identification: Per Dreyer, IC 4969 (= Frost #1191, 1860 RA 20 01 59, NPD 144 20) is "faint, very small, round". The position precesses to RA 20 12 49.1, Dec -53 55 19, only an arcmin west of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.65 by 0.6 arcmin.
DSS image of region near spiral galaxy IC 4969
Above, a 12 arcmin wide DSS image centered on IC 4969
Below, a 0.9 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4969

IC 4970 (= PGC 64415)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.9 lenticular galaxy (type (R)SB0(rs)a pec?) in Pavo (RA 20 16 57.2, Dec -70 45 00)
Historical Identification: Per Dreyer, IC 4970 (= DeLisle Stewart #657, 1860 RA 20 02 08, NPD 161 11) has a "brighter middle, near (NGC) 6872". The position precesses to RA 20 16 56.5, Dec -70 45 57, within the northern outline of NGC 6872 and less than an arcmin south of the galaxy listed above; and the absence of any other companion to the giant spiral makes the identification certain.
Physical Information: Apparent size 1.0 by 0.4 arcmin.
Capella Observatory image of lenticular galaxy IC 4970 and NGC 6872, superimposed on a DSS image of region near the interacting pair; the northwestern outskirts of NGC 6876 are also shown
Above, a 12 arcmin wide image centered on IC 4970, showing NGC 6872 and part of NGC 6876
(Image Credit & © Capella Observatory (superimposed on DSS background); used by permission)
Below, a 1.5 arcmin wide Gemini Observatory image of IC 4970 and part of NGC 6872
(Image Credit & © below Sydney Girls High School Astronomy Club, Travis Rector (University of Alaska, Anchorage),
Ángel López-Sánchez (Australian Astronomical Observatory/Macquarie University), and the Australian Gemini Office)

Gemini Observatory image of lenticular galaxy IC 4970, also showing part of NGC 6872

IC 4971 (= PGC 64417)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 15.3 spiral galaxy (type Sbc?) in Pavo (RA 20 17 02.9, Dec -70 37 14)
Historical Identification: Per Dreyer, IC 4971 (= DeLisle Stewart #658, 1860 RA 20 02 14, NPD 161 03) is "extremely faint, very small". The position precesses to RA 20 16 59.0, Dec -70 37 56, only 0.7 arcmin south southwest of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.75 by 0.25 arcmin.
DSS image of region near spiral galaxy IC 4971, also showing IC 4967
Above, a 12 arcmin wide DSS image centered on IC 4971, also showing IC 4967
Below, a 1.0 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4971

IC 4972 (= PGC 64436)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 14.6 spiral galaxy (type Sb?) in Pavo (RA 20 17 43.0, Dec -70 54 51)
Historical Identification: Per Dreyer, IC 4972 (= DeLisle Stewart #661, 1860 RA 20 02 48, NPD 161 20) is "extremely faint, very small, extremely extended 15°". The position precesses to RA 20 17 39.5, Dec -70 54 49, less than 0.3 arcmin west of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.1 by 0.15 arcmin.
Capella Observatory image of region near spiral galaxy IC 4972, also showing NGC 6876 and NGC 6877
Above, a 12 arcmin wide image centered on IC 4972, also showing NGC 6876 and NGC 6877
(Image Credits & © above and below Capella Observatory; used by permission)
Below, a 1.5 arcmin wide image of the galaxy
Capella Observatory image of spiral galaxy IC 4972

IC 4973 (= PGC 64337)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 15.0 spiral galaxy (type SBcd pec?) in Pavo (RA 20 14 34.2, Dec -58 22 21)
Historical Identification: Per Dreyer, IC 4973 (= DeLisle Stewart #656, 1860 RA 20 03 06, NPD 148 47) is "most extremely faint, very small, round". The position precesses to RA 20 14 35.4, Dec -58 22 04, on the northeast rim of the galaxy listed above and there is nothing else nearby, so the identification is certain. (Note: The position listed above is for the center of the bar-like structure, as I suspect that the "nucleus" to its north is actually a superimposed star.)
Physical Information: Apparent size 0.65 by 0.5 arcmin.
DSS image of region near spiral galaxy IC 4973
Above, a 12 arcmin wide DSS image centered on IC 4973
Below, a 0.9 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4973

IC 4974 (= PGC 64366 + PGC 64361)
Discovered (Aug 15, 1901) by
DeLisle Stewart
A pair of galaxies in Pavo
PGC 64366 = A magnitude 14.4 spiral galaxy (type Sa pec?) at RA 20 15 26.0, Dec -61 51 26
PGC 64361 = A magnitude 14.7 spiral galaxy (type Sb pec?) at RA 20 15 26.9, Dec -61 51 46
Historical Identification: Per Dreyer, IC 4974 (= DeLisle Stewart #659, 1860 RA 20 03 12, NPD 152 17) is "extremely faint, extremely small, round, brighter middle, star 1 arcmin to southwest". The position precesses to RA 20 15 20.6, Dec -61 51 59, only about 0.8 arcmin southwest of the pair of galaxies listed above, but it is the star to their southwest that makes the identification certain.
The apparent size of PGC 64366 is about 0.7 by 0.5 arcmin; of PGC 64361, about 0.6 by 0.4 arcmin.
DSS image of region near the pair of spiral galaxies that comprise IC 4974, also showing IC 4976
Above, a 12 arcmin wide DSS image centered on IC 4974, also showing IC 4976
Below, a 1.2 arcmin wide DSS image of the galaxies
DSS image of the pair of spiral galaxies that comprise IC 4974

IC 4975 (= PGC 64325)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 13.3 lenticular galaxy (type (R')SB0(rs)?) in Telescopium (RA 20 14 03.1 Dec -52 43 18)
Historical Identification: Per Dreyer, IC 4975 (= Frost #1192, 1860 RA 20 03 20, NPD 143 09) has a "brighter middle, magnitude 15". The position precesses to RA 20 14 00.1, Dec -52 44 06, just under an arcmin south southwest of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.9 by 0.9 arcmin.
DSS image of region near lenticular galaxy IC 4975
Above, a 12 arcmin wide DSS image centered on IC 4975
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of lenticular galaxy IC 4975

IC 4976 (= PGC 64374)
Discovered (Aug 15, 1901) by
DeLisle Stewart
A magnitude 14.7 spiral galaxy (type (R)SB(r)a?) in Pavo (RA 20 15 41.1, Dec -61 52 29)
Historical Identification: Per Dreyer, IC 4976 (= DeLisle Stewart #660, 1860 RA 20 03 24, NPD 152 18) is "extremely faint, extremely small, round, brighter middle, star 3 arcmin to northwest". The position precesses to RA 20 15 32.7, Dec -61 52 57, just over an arcmin west of the galaxy listed above, which is similar to the error Stewart made for IC 4974, discovered by him on the same day on the same plate; and as in the case of that pair, the star (in this case nearly 3 arcmin) to the west makes the identification certain.
Physical Information: Apparent size 0.75 by 0.45 arcmin.
DSS image of region near spiral galaxy IC 4976, also showing the pair of galaxies that comprise IC 4974
Above, a 12 arcmin wide DSS image centered on IC 4976, also showing IC 4974
Below, a 1.0 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4976

IC 4977
Recorded (Jun 21, 1898) by
Guillaume Bigourdan
A lost or nonexistent object in Capricornus (RA 20 11 53.9, Dec -21 38 15)
Historical Identification: Per Dreyer, IC 4977 (= Bigourdan #435, 1860 RA 20 03 40, NPD 112 03) is "stellar, close to 13th magnitude star". The position precesses to RA 20 11 53.9, Dec -21 38 15 (whence the position above), but though there is a suitable star nearby, there is nothing else anywhere near there, so it appears that the object is lost or nonexistent. (Per Corwin, one of Bigourdan's appendices states that he took this for a comet, with a notation that suggests it might have been Comet Giacobini, in which case backtracking the comet's orbit might show that it was near the position Bigourdan recorded for his #435 on the date in question; but though that would provide an interesting solution to the question of what Bigourdan observed, it would still make IC 4977 a nonexistent object as far as a list of nebulae and clusters is concerned.)
DSS image of region near the apparently nonexistent IC 4977
Above, a 12 arcmin wide DSS image centered on the position of IC 4977

IC 4978 (= PGC 64338)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 14.6 spiral galaxy (type Sa?) in Telescopium (RA 20 14 37.6, Dec -54 25 19)
Historical Identification: Per Dreyer, IC 4978 (= Frost #1193, 1860 RA 20 03 40, NPD 144 51) has a "brighter middle, magnitude 15". The position precesses to RA 20 14 33.2, Dec -54 26 01, just under an arcmin southwest of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.6 by 0.3 arcmin.
DSS image of region near spiral galaxy IC 4978
Above, a 12 arcmin wide DSS image centered on IC 4978
Below, a 0.8 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4978

IC 4979 (= PGC 64342)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 14.1 spiral galaxy (type SAB(r)cd?) in Telescopium (RA 20 14 41.7, Dec -53 27 31)
Historical Identification: Per Dreyer, IC 4979 (= Frost #1194, 1860 RA 20 03 49, NPD 143 54) is "very faint, small, round, diffuse". The position precesses to RA 20 14 34.5, Dec -53 29 00, about 1.8 arcmin southwest of the galaxy listed above, but there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.05 by 0.9 arcmin.
DSS image of region near spiral galaxy IC 4979
Above, a 12 arcmin wide DSS image centered on IC 4979
Below, a 1.3 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4979

IC 4980 (= PGC 64367)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 13.1 lenticular galaxy (type SB0/a?(s) pec) in Pavo (RA 20 15 28.8, Dec -57 54 45)
Historical Identification: Per Dreyer, IC 4980 (= DeLisle Stewart #662, 1860 RA 20 04 07, NPD 148 19) is "very faint, small, a little extended 130°, star 2 arcmin to south". The position precesses to RA 20 15 31.0, Dec -57 53 54, about 0.9 arcmin north northeast of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.4 by 0.6 arcmin.
DSS image of region near lenticular galaxy IC 4980
Above, a 12 arcmin wide DSS image centered on IC 4980
Below, a 1.6 arcmin wide DSS image of the galaxy
DSS image of lenticular galaxy IC 4980

IC 4981 (= PGC 64486)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.1 irregular galaxy (type Irr pec) in Pavo (RA 20 19 39.1, Dec -70 50 54)
Historical Identification: Per Dreyer, IC 4981 (= DeLisle Stewart #663, 1860 RA 20 04 56, NPD 161 16) is "extremely faint, extremely small, star near". The position precesses to RA 20 19 43.0, Dec -70 50 28, only half an arcmin northeast of the galaxy listed above, and the star on its northern rim makes the identification certain (though it does seem odd that Stewart did not bother to mention the object's proximity to the much brighter NGC 6880).
Physical Information: Apparent size 1.3 by 0.35 arcmin.
Capella Observatory image of region near irregular galaxy IC 4981, also showing NGC 6877, NGC 6880 and part of NGC 6876
Above, a 12 arcmin wide image centered on IC 4981, also showing NGC 6876, 6877 and 6880
(Image Credits & © above and below Capella Observatory; used by permission)
Below, a 1.4 arcmin wide image of the galaxy
Capella Observatory image of irregular galaxy IC 4981

IC 4982 (= PGC 64498)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 14.4 peculiar galaxy (type SB? pec) in Pavo (RA 20 20 20.8, Dec -71 00 28)
Historical Identification: Per Dreyer, IC 4982 (= DeLisle Stewart #665, 1860 RA 20 05 31, NPD 161 26) is "very faint, brighter middle". The position precesses to RA 20 20 21.5, Dec -71 00 22, well within the northeastern outline of the galaxy listed above and there is nothing else nearby, so the identification is certain. IC 4982 is almost certainly interacting with the galaxy to its south (PGC 270900), but unlike some systems in which both components are treated as part of the NGC/IC object, IC 4982 seems to be treated as being only the brighter northern component, and is therefore treated as such here as well.
Physical Information: Based on a recessional velocity of 6180 km/sec, IC 4982 is about 285 million light years away. Given that and its apparent size of 0.55 by 0.45 arcmin, IC 4982 is about 45 thousand light years across, and the 0.65 by 0.5 arcmin extent of the overall system corresponds to about 55 thousand light years.
Capella Observatory image of region near peculiar galaxy IC 4982 (superimposed on a DSS background to fill in missing areas), also showing IC 4985 and PGC 270900
Above, a 12 arcmin wide image centered on IC 4982, also showing IC 4985 and PGC 270900
(Image Credit & © above Capella Observatory (superimposed on DSS background); used by permission)
Below, a 0.8 arcmin wide DSS image of the galaxy, also showing PGC 270900
DSS image of peculiar galaxy IC 4982, also showing PGC 270900

PGC 270900
Not an IC object but listed here since apparently interacting with
IC 4982
A magnitude 16.5(?) galaxy (type unknown) in Pavo (RA 20 20 20.8, Dec -71 00 46)
Apparently interacting with IC 4982, which see for images of the pair. No independent distance estimate is available, but if actually interacting with IC 4982, it is presumably at the same distance (about 285 million light years). Given that and its apparent size of 0.25 by 0.15 arcmin, PGC 270900 is about 20 thousand light years across.

IC 4983 (= PGC 64382)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 13.6 spiral galaxy (type SB(rs)c?) in Telescopium (RA 20 16 05.8, Dec -52 05 11)
Historical Identification: Per Dreyer, IC 4983 (= Frost #1195, 1860 RA 20 05 34, NPD 142 30) is "very faint, considerably small, round, a little brighter middle, diffuse". The position precesses to RA 20 16 07.9, Dec -52 04 43, just off the northeastern rim of the galaxy listed above and there is nothing comparable nearby, so the identification is certain.
Physical Information: Apparent size 0.9 by 0.9 arcmin.
DSS image of region near spiral galaxy IC 4983
Above, a 12 arcmin wide DSS image centered on IC 4983
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4983

IC 4984 (= PGC 64388)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 14.6 spiral galaxy (type Sab?) in Telescopium (RA 20 16 17.4, Dec -52 42 13)
Historical Identification: Per Dreyer, IC 4984 (= Frost #1196, 1860 RA 20 05 39, NPD 143 08) is "very faint, small, round, diffuse, (NGC) 6887 to east". The position precesses to RA 20 16 17.6, Dec -52 42 42, less than half an arcmin south of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.8 by 0.35 arcmin.
DSS image of region near spiral galaxy IC 4984
Above, a 12 arcmin wide DSS image centered on IC 4984
Below, a 50 arcsec wide DSS image of the galaxy
DSS image of spiral galaxy IC 4984

IC 4985 (= PGC 64505)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.9 spiral galaxy (type SABab?) in Pavo (RA 20 20 44.0, Dec -70 59 12)
Historical Identification: Per Dreyer, IC 4985 (= DeLisle Stewart #666, 1860 RA 20 05 55, NPD 161 25) is "very faint, brighter middle". The position precesses to RA 20 20 44.6, Dec -70 59 17, almost dead center on the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.7 by 0.6 arcmin.
Capella Observatory image of region near spiral galaxy IC 4985, superimposed on a DSS background to fill in missing areas; also showin is IC 4982
Above, a 12 arcmin wide image centered on IC 4985, also showing IC 4982
(Image Credit & © above and below Capella Observatory (above, superimposed on DSS background); used by permission)
Below, a 1.0 arcmin wide Capella Observatory image of the galaxy
Capella Observatory image of spiral galaxy IC 4985

IC 4986 (= PGC 64423)
Discovered (Oct 3, 1901) by
DeLisle Stewart
A magnitude 13.6 spiral galaxy (type SAB(s)dm?) in Telescopium (RA 20 17 11.3, Dec -55 02 09)
Historical Identification: Per Dreyer, IC 4986 (= DeLisle Stewart #664, 1860 RA 20 06 16, NPD 145 27) is "most extremely faint, small, considerably extended 0°, between 2 faint stars". The position precesses to RA 20 17 12.6, Dec -55 01 34, within the northern outline of the galaxy, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 2.0 by 0.8 arcmin.
DSS image of region near spiral galaxy IC 4986
Above, a 12 arcmin wide DSS image centered on IC 4986
Below, a 2.4 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4986

IC 4987 (= PGC 64428)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 14.5 spiral galaxy (type SAB(s)bc?) in Telescopium (RA 20 17 19.4, Dec -52 16 45)
Historical Identification: Per Dreyer, IC 4987 (= Frost #1197, 1860 RA 20 06 46, NPD 142 43) is "faint, very small, round, a little brighter middle". The position precesses to RA 20 17 20.8, Dec -52 17 31, about 0.8 arcmin south southeast of the galaxy listed above and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.0 by 0.6 arcmin.
DSS image of region near spiral galaxy IC 4987
Above, a 12 arcmin wide DSS image centered on IC 4987
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4987

IC 4988
Recorded (Sep 24, 1900) by
DeLisle Stewart
A lost or nonexistent object in Pavo (RA 20 21 46.0, Dec -69 23 04)
Historical Identification: Per Dreyer, IC 4988 (= DeLisle Stewart #667, 1860 RA 20 07 37, NPD 159 49) is a "hazy patch, perhaps a star?; suspected". The position precesses to RA 20 21 46.0, Dec -69 23 04 (whence the position above), but there is nothing there. Corwin suggests that what Stewart recorded might have been one of the asterisms in the area, but feels that nothing stands out, and only an examination of the original plate would reveal what (if anything) this entry represents. So at least for now IC 4988 is lost or nonexistent.
DSS image of region near the apparently nonexistent IC 4988
Above, a 12 arcmin wide DSS image centered on the position of IC 4988

IC 4989 (= PGC 64476)
Discovered (May 17, 1904) by
Royal Frost
A magnitude 14.5 spiral galaxy (type Sbc?) in Pavo (RA 20 19 23.7, Dec -58 33 06)
Historical Identification: Per Dreyer, IC 4989 (= Frost #1198, 1860 RA 20 08 00, NPD 148 59) is "considerably small, much extended 175°, spiral, faint star in middle". The position precesses to RA 20 19 27.8, Dec -58 33 14, only half an arcmin east of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.1 by 0.3 arcmin.
DSS image of region near spiral galaxy IC 4989
Above, a 12 arcmin wide DSS image centered on IC 4989
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4989

IC 4990 (= PGC 64520)
Discovered (Sep 24, 1900) by
DeLisle Stewart
A magnitude 15.0 spiral galaxy (type SAB(s)c? pec) in Pavo (RA 20 21 25.4, Dec -66 53 26)
Historical Identification: Per Dreyer, IC 4990 (= DeLisle Stewart #668, 1860 RA 20 08 10, NPD 157 20) is "extremely faint, extremely small, considerably extended 15°, brighter middle, suspected". The position precesses to RA 20 21 29.1, Dec -66 54 02, about 0.7 arcmin southeast of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.1 by 0.35 arcmin, including the southern "tail".
DSS image of region near spiral galaxy IC 4990, also showing IC 4993
Above, a 12 arcmin wide DSS image centered on IC 4990, also showing IC 4993
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4990

IC 4991 (almost certainly not =
PGC 64450)
Recorded (Sep 23, 1897) by Lewis Swift
A lost or nonexistent object in Sagittarius (RA 20 17 45.2, Dec -41 34 57)
Historical Identification: Per Dreyer, IC 4991 (= Swift list XI (#191), 1860 RA 20 08 15, NPD 132 00.6) is "very faint, considerably small, round" (Swift's paper adds "no bright star near"). The position precesses to RA 20 17 45.2, Dec -41 34 57 (whence the position above), but there is nothing there or anywhere near there that fits Swift's description. Despite that, the more than half degree distant PGC 64450 is identified as IC 4991 in almost all references. Arguments against (and counter-arguments for) this identification include: (1) The galaxy has a large position error in right ascension (over half a minute of time) and declination (over half a degree), but in his later years Swift often made errors that large or larger. (2) The galaxy seems too bright to be called "very faint", but (as pointed out by Corwin) it would have been very low in the southern sky at Swift's location, and due to atmospheric extinction (scattering and absorption of light caused by air lying between us and the object) would have looked fainter than usual. But most tellingly, (3) Swift states that there are "no bright stars near", whereas there are 8th and 9th magnitude stars not far from the galaxy, and even as low in the sky as the field was, Swift would have certainly noted their presence if he had really been observing PGC 64450. As a result, it is almost certain that PGC 64450 is not IC 4991, and what (if anything) Swift observed should be listed as lost or nonexistent. However, given the history of PGC 64450's (mis)identification as IC 4991, it is discussed in the following entry.
DSS image of region near Swift's position for the apparently nonexistent IC 4991
Above, a 12 arcmin wide DSS image centered on Swift's position for the apparently nonexistent IC 4991

PGC 64450 (= ESO 340-011, and almost certainly not =
IC 4991)
Almost certainly not an IC object but listed here because usually (mis)identified as IC 4991
A magnitude 11.5 lenticular galaxy (type SA(r)0?) in Sagittarius (RA 20 18 23.3, Dec -41 03 00)
Historical Identification: As noted in the entry for IC 4991, PGC 64450 is listed as that IC object in almost every modern reference, so even if it could be proven beyond a shadow of a doubt that it is not IC 4991, its (mis)identification as that IC object will probably never be abandoned (hence the need for this entry).
Physical Information: Based on a recessional velocity of 5650 km/sec, PGC 64450 is about 265 million light years away. Given that and its apparent size of about 3.2 by 2.1 arcmin, it is about 245 thousand light years across. The galaxy to its east (PGC 64456) has a similar recessional velocity (5885 km/sec), so the two are probably at a similar distance from us (their Hubble distances differ by only 10 million light years), and might be physical companions in the same sense as our galaxy and the Andromeda Galaxy; but they can't be as close to each other as they appear, as substantial gravitational interaction and physical distortion would accompany such a small separation.
Carnegie-Irvine Galaxy Survey image of lenticular galaxy PGC 64450, which is usually (mis)identified as IC 4991, superimposed on a DSS image of the region near the galaxy
Above, the image below superimposed on a 12 arcmin wide DSS image centered on PGC 64450
(Also shown is PGC 64456, which may be a companion of PGC 64450)
Below, a 3.6 arcmin wide image of PGC 64450 (Image Credit & © Carnegie-Irvine Galaxy Survey; used by permission)
Carnegie-Irvine Galaxy Survey image of lenticular galaxy PGC 64450, which is usually (mis)identified as IC 4991
Below, a 1.2 degree wide DSS image centered on Swift's position for IC 4991, also showing PGC 64450
(The box near the galaxy represents a position half a minute of time and half a degree "off" Swift's position)DSS image of region near Swift's position for the probably nonexistent IC 4991, also showing PGC 64450, which is usually (mis)identified as IC 4991

IC 4992 (= PGC 64597)
Discovered (Sep 21, 1900) by
DeLisle Stewart
A magnitude 13.8 spiral galaxy (type SB(s)c?) in Pavo (RA 20 23 27.0, Dec -71 33 55)
Historical Identification: Per Dreyer, IC 4992 (= DeLisle Stewart #670, 1860 RA 20 08 27, NPD 162 00) is "very faint, small, extremely extended 65°, 9th magnitude star 2 arcmin to northeast". The position precesses to RA 20 23 28.7, Dec -71 33 51, almost dead center on the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 2.2 by 0.2 arcmin. A "superthin" galaxy?
DSS image of region near spiral galaxy IC 4992
Above, a 12 arcmin wide DSS image centered on IC 4992
Below, a 2.1 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4992

IC 4993 (= PGC 64541)
Discovered (Sep 24, 1900) by
DeLisle Stewart
A magnitude 15.1 spiral galaxy (type Sm pec?) in Pavo (RA 20 21 56.3, Dec -66 59 07)
Historical Identification: Per Dreyer, IC 4993 (= DeLisle Stewart #669, 1860 RA 20 08 39, NPD 157 26) is "extremely faint, very small, round, brighter middle, suspected". The position precesses to RA 20 21 59.3, Dec -66 59 57, about 0.9 arcmin south southeast of the galaxy listed above, the description fits and there is nothing else nearby, so the identification seems certain.
Physical Information: Apparent size 0.45 by 0.35 arcmin.
DSS image of region near spiral galaxy IC 4993, also showing IC 4990
Above, a 12 arcmin wide DSS image centered on IC 4993, also showing IC 4990
Below, a 0.6 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4993

IC 4994 (= PGC 64489)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 12.9 lenticular galaxy (type SA0/a? pec) in Telescopium (RA 20 19 44.5, Dec -53 26 50)
Historical Identification: Per Dreyer, IC 4994 (= Frost #1199, 1860 RA 20 09 02, NPD 143 53) has a "brighter middle, magnitude 15". The position precesses to RA 20 19 44.2, Dec -53 27 07, just inside the southern outline of the galaxy listed above, and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.0 by 0.8 arcmin.
DSS image of region near lenticular galaxy IC 4994
Above, a 12 arcmin wide DSS image centered on IC 4994
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of lenticular galaxy IC 4994

IC 4995 (= PGC 64491)
Discovered (Aug 31, 1904) by
Royal Frost
A magnitude 13.3 spiral galaxy (type Sa?) in Telescopium (RA 20 19 59.0, Dec -52 37 19)
Historical Identification: Per Dreyer, IC 4995 (= Frost #1200, 1860 RA 20 09 28, NPD 143 03) has a "brighter middle, magnitude 14". The position precesses to RA 20 20 03.7, Dec -52 37 03, less than 0.8 arcmin east northeast of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 0.9 by 0.65 arcmin. Listed as a Seyfert galaxy (type Sy 2).
DSS image of region near spiral galaxy IC 4995
Above, a 12 arcmin wide DSS image centered on IC 4995
Below, a 1.2 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4995
Below, a 0.2 arcmin wide image of the galaxy's core (Image Credit: Hubble Legacy Archive, Courtney Seligman)
'Raw' HST image of spiral galaxy IC 4995

IC 4996 (= OCL 158)
Discovered (Sep 20, 1786) by
William Herschel
Discovered (Jun 13, 1896) by Hugo Clemens
Discovered (Oct 9, 1903) by Frank Bellamy
A magnitude 7.3 open cluster (type II3p) in Cygnus (RA 20 16 31.7, Dec +37 38 35)
Historical Identification: Per Dreyer, IC 4996 (= Bellamy (M.N., lxiv.), 1860 RA 20 11 20, NPD 52 25) is a "cluster, with stars from 8th to 13th magnitude". The position precesses to RA 20 16 29.3, Dec +38 00 48, but there is nothing there. The problem (as pointed out by Corwin) is that although Bellamy measured the position and magnitude of 103 stars in the neighborhood of the cluster he did not bother to give a position for the cluster itself, so Dreyer had to examine the individual stellar positions to estimate the cluster's position; and although he obtained a good estimate of its right ascension, his declination is about 22 arcmin north of the median declination of the stars observed by Bellamy (for which I obtained a value of (1900) +37 20 by simply counting the number of stars at each arcminute of declination). Applying a correction for that error to Dreyer's 1900 coordinates yields a precessed position of RA 20 16 31.1, Dec +37 38 31, right on the core of the cluster listed above, making the identification of IC 4996 as that cluster certain.
Discovery Notes: (Per Steinicke) Clemens noted a cluster of 12 stars on plate 922 of the Photographische Himmelskarte (Photographic Map of the Sky), which was published in volume 2 of the Publications of the Astrophysical Observatory of Potsdam. Since the plate was taken on Jun 13, 1896, Clemens was a prior discoverer of the cluster; but apparently Dreyer was unaware of the Potsdam publication (or at the very least, of Clemens' note about the cluster) when he compiled the IC2, so Bellamy was credited with the discovery. And apparently (again per Steinicke) the cluster was first observed by William Herschel and is included in one of his Sweep Records [RAS Archive W. Herschel 2/3.5], though not in his published works, so no one could have known of his earlier observation.
Physical Information: Corwin notes that Bellamy's measurements cover a region about 15 arcmin across, but suspects that most of the outlying "members" of the cluster are merely an enhancement of the general background of stars in the region, and not part of a real cluster. Steinicke states that the cluster is about 7 arcmin across, but as seen in the image below the central condensation is only about half that size.
Capella Observatory image of region near open cluster IC 4996
Above, a 12 arcmin wide image centered on IC 4996 (Image Credit & © Capella Observatory; used by permission)

IC 4997
Discovered (1896) by
Williamina Fleming
Discovered (1896?) by Gustav Gruss
A magnitude 10.5 planetary nebula in Sagitta (RA 20 20 08.8, Dec +16 43 53)
Historical Identification: Per Dreyer, IC 4997 (= Fleming #78, Gruss, 1860 RA 20 13 46, NPD 73 42) is a "planetary, stellar". The position precesses to RA 20 20 10.4, Dec +16 44 19, only 0.6 arcmin northeast of the planetary nebula listed above, so the identification is certain.
Discovery Notes: The nebula was independently observed by Gruss and Fleming at about the same time, and the exact dates of observation are unknown, so they share credit for the discovery (one of many by Fleming, but the only one by Gruss).
Physical Information: Apparent size 13 by 11 arcsec for faint outer regions, 4 by 2.5 arcsec for brighter central regions.
DSS image of region near planetary nebula IC 4997
Above, a 12 arcmin wide DSS image centered on IC 4997 (the bright star in the middle)
Below, a 1.5 arcmin wide DSS image centered on the planetary nebula
DSS image of planetary nebula IC 4997
Below, a 0.3 arcmin wide image of the planetary nebula (Image Credit Hubble Legacy Archive, Courtney Seligman)
'Raw' HST image of planetary nebula IC 4997

IC 4998 (possibly =
IC 5018 and perhaps = PGC 64546)
Recorded (Sep 11, 1897) by Lewis Swift (and later listed as IC 4998)
Possibly also recorded (Sep 11, 1897) by Lewis Swift (and later listed as IC 5018)
Probably a lost or nonexistent object in Sagittarius (RA 20 23 59.3, Dec -38 14 40)
but perhaps PGC 64546 = A magnitude 13.2 spiral galaxy (type SB(s)c?) at RA 20 22 10.5, Dec -38 18 30
Historical Identification: Per Dreyer, IC 4998 (= Swift list XII (#17), 1860 RA 20 14 47, NPD 128 41.4) is "extremely faint, pretty small, round, between two 8.5 magnitude stars to southwest and northeast". The position precesses to RA 20 23 59.3, Dec -38 14 40 (whence the position above), but there is nothing there or anywhere near there. As noted above, there is a remote possibility that this may be PGC 64546, but Swift's description of the star field does not match that near the galaxy, so although it is usually listed as IC 4998, that identification should be treated with extreme caution; as a result I have listed IC 4998 as probably lost or nonexistent, and dealt with PGC 64546 in the following entry.
Discovery Notes: Per Corwin, it is possible that IC 4998 may be the same "object" as IC 5018, which is also almost certainly lost or nonexistent. The difference in their listed positions is huge, but their descriptions are identical, and it is not terribly unusual for observers to record multiple observations of a given object on the same evening. Traditional observations were done by sweeping through a region in right ascension, then slightly changing the declination and sweeping through it again. Sometimes the same object would be observed near the top or bottom of one sweep, and in the opposite position on another sweep. If its positions were correctly measured and reduced the fact that it was the same object would soon become obvious; but if any mistakes were made, duplicate listings would result. In this case the huge difference in positions may be real, and the identical descriptions merely coincidental; but it is possible that the positions are incredibly poor, and the descriptions represent the same object. However, as noted above, the only object (PGC 64546) anywhere near Swift's position for either IC entry does not have a star field matching his descriptions, so although it is conceivable that IC 4998 and IC 5018 may represent the same object, just what object is even more of a mystery.
DSS image of region near Swift's position for the probably lost or nonexistent IC 4998
Above, a 12 arcmin wide DSS image centered on Swift's position for IC 4998

PGC 64546 (probably not =
IC 4998)
Probably not an IC object but listed here since often (mis)identified as IC 4998
A magnitude 13.2 spiral galaxy (type SB(s)c?) in Sagittarius (RA 20 22 10.5, Dec -38 18 30)
Historical Identification: See IC 4998 for a discussion of why this is probably not that IC object.
Physical Information: Apparent size about 1.65 by 1.15 arcmin.
DSS image of region near spiral galaxy PGC 64546, which is often (mis)identified as IC 4998
Above, a 12 arcmin wide DSS image centered on PGC 64546, which may or may not be IC 4998
Below, a 1.8 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy PGC 64546, which is often (mis)identified as IC 4998

IC 4999 (= PGC 64613)
Discovered by
Edward Barnard
A magnitude 12.5 spiral galaxy (type SAB(rs)cd?) in Capricornus (RA 20 23 56.3, Dec -26 00 53)
Historical Identification: Per Dreyer, IC 4999 (= Barnard, 1860 RA 20 15 16, NPD 116 27.3) is "very faint, pretty large, round, among stars". The position precesses to RA 20 23 41.9, Dec -26 00 33, over 3 arcmin west of the galaxy listed above, but there is nothing else nearby and the description fits, so the identification is essentially certain.
Physical Information: Apparent size 1.95 by 1.0 arcmin.
DSS image of region near spiral galaxy IC 4999
Above, a 12 arcmin wide DSS image centered on IC 4999
Below, a 2.1 arcmin wide DSS image of the galaxy
DSS image of spiral galaxy IC 4999
Celestial Atlas
(IC 4900 - 4949) ←IC Objects: IC 4950 - 4999→ (IC 5000 - 5049)