Historical Identification: Per Dreyer, IC 4200 (= Frost #1041, 1860 RA 13 01 15, NPD 141 13) is "faint, brighter middle, magnitude 14.5". The position precesses to RA 13 09 31.7, Dec -51 57 53, within the periphery of the galaxy, so the identification is certain.
Physical Information: A Seyfert galaxy (type Sy 1). Based on a recessional velocity of 3895 km/sec, IC 4200 is about 180 million light years away, in good agreement with redshift-independent distance estimates of 140 to 180 million light years. Given that and its apparent size of 1.8 by 1.3 arcmin, it is about 95 thousand light years across. The unusual appearance of the galaxy and its substantial population of relatively young stars (about a third the age of our Sun) is interpreted as the result of the merger of two galaxies about 2000 million years ago.

Historical Identification: Per Dreyer, IC 4201 (= Wolf list V #228, 1860 RA 13 01 19, NPD 53 25.0) is "faint, small, irregular figure, nuclear". The position precesses to RA 13 07 51.2, Dec +35 50 05, right on the galaxy, so the identification is certain.
Physical Information: Based on a recessional velocity of 11245 km/sec, a straightforward calculation indicates that IC 4201 is about 525 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 500 million light years away at the time the light by which we see it was emitted, about 510 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 0.7 by 0.7 arcmin, it is about 100 thousand light years across.

Historical Identification: Per Dreyer, IC 4201 (= Javelle #1236, 1860 RA 13 01 46, NPD 64 33.0) is "faint, considerably small, extended, gradually brighter middle". The position precesses to RA 13 08 31.7, Dec +24 42 06, right on the galaxy, so the identification is certain.
Physical Information: Based on a recessional velocity of 7125 km/sec, IC 4202 is about 330 million light years away, in good agreement with redshift-independent distance estimates of 330 to 370 million light years. Given that and its apparent size of about 1.8 by 0.25 arcmin, it is about 175 thousand light years across.

Historical Identification: Per Dreyer, IC 4203 (= Wolf list V #229, 1860 RA 13 01 53, NPD 48 49.5) is "extremely faint, small, diffuse". The position precesses to RA 13 08 18.0, Dec +40 25 36, nearly on the star listed above. Even more convincingly, per Corwin a print of the original plate shows Wolf's mark right on the star, so the identification is certain.

Historical Identification: Per Dreyer, IC 4204 (= Wolf list V #230, 1860 RA 13 01 55, NPD 49 47.5) is "faint, considerably small, possibly spiral". The position precesses to RA 13 08 21.5, Dec +39 27 36, right on the galaxy, so the identification is certain. (Note: IC 4204 is not listed in LEDA, but PGC 45534 is.)
Physical Information: Based on a recessional velocity of 3305 km/sec, IC 4204 is about 155 million light years away, in good agreement with redshift-independent distance estimates of 145 to 170 million light years. Given that and its apparent size of about 1.2 by 0.2 arcmin, it is about 55 thousand light years across.

Historical Identification: Per Dreyer, IC 4205 (= Swift list XI (#151), 1860 RA 13 02 44, NPD 36 23.3) is "very faint, pretty large, round (= IC 853?)". The position precesses to RA 13 08 43.4, Dec +52 51 51, but there is nothing there. However, per Corwin, if what Swift observed was his son Edward's IC 853, the RA is reasonably accurate and the declination's 5+ minute error matches a similar error in the declination of IC 3791, observed by Swift on the same night, which would be consistent with a 'minor' error in the setting circles on his telescope. It is therefore essentially certain that Dreyer's suggestion that IC 4205 is identical to IC 853 was correct. (Note: IC 4205 is not listed in LEDA, but IC 853 is.)
Physical Information: Given the duplicate entry, see IC 853 for anything else.

Historical Identification: Per Dreyer, IC 4206 (= Wolf list V #231, 1860 RA 13 02 56, NPD 50 13.8) is "pretty faint, small, irregular figure, nuclear". The position precesses to RA 13 09 22.5, Dec +39 01 22, right on the star listed above. Even more convincingly, per Corwin a print of the original plate shows Wolf's mark right on the star, so the identification is certain.

Historical Identification: Per Dreyer, IC 4207 (= Wolf list V #232, 1860 RA 13 02 59, NPD 51 25.8) is "very faint, considerably small, irregular figure". The position precesses to RA 13 09 27.3, Dec +37 49 22, right on the galaxy, so the identification is certain. (Note: IC 4207 is not listed in LEDA, but PGC 2110457 is.)
Physical Information: Based on a recessional velocity of 21045 km/sec, a straightforward calculation indicates that IC 4207 is about 980 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 905 million light years away at the time the light by which we see it was emitted, about 935 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 0.5 by 0.25 arcmin, it is about 130 thousand light years across.

Historical Identification: Per Dreyer, IC 4208 (= Wolf list V #233, 1860 RA 13 03 09, NPD 51 59.8) is "faint, considerably small, brighter middle, spiral". The position precesses to RA 13 09 38.1, Dec +37 15 23, right on the star listed above. Even more convincingly, per Corwin a print of the original plate shows Wolf's mark right on the star, so the identification is certain.

Historical Identification: Per Dreyer, IC 4209 (= DeLisle Stewart #371, 1860 RA 13 03 20, NPD 96 25) is "extremely faint, extremely small, considerably extended 100°". The position precesses to RA 13 10 36.7, Dec -07 09 47, a little over 4 arcmin east of the galaxy listed above, but since its appearance perfectly matches the IC2 description and there is nothing else nearby, the identification is essentially certain. (Per Corwin, this is one of four nebulae found by Stewart on Harvard plate A3776, all of which have poor positions; but for the reasons already stated, he made the same identification long before I looked into the matter.)
Physical Information: Based on a recessional velocity of 6735 km/sec, IC 4209 is about 315 million light years away, in reasonable agreement with redshift-independent distance estimates of 330 to 360 million light years. Given that and its apparent size of about 1.4 by 0.55 arcmin, it is about 130 thousand light years across.

Historical Identification: Per Dreyer, IC 4210 (= Bigourdan #410, 1860 RA 13 04 07, NPD 59 34) is "extremely faint, small, diffuse". The position precesses to RA 13 10 45.9, Dec +29 41 14, about 1.5 arcmin southwest of the galaxy listed above. This is not up to Bigourdan's usual accuracy, but there is nothing else nearby that fits the description, and the identification is considered certain.
Physical Information: Based on a recessional velocity of 6365 km/sec, IC 4210 is about 295 million light years away, in fair agreement with a redshift-independent distance estimate of 340 million light years. Given that and its apparent size of about 0.85 by 0.5 arcmin, it is about 75 thousand light years across. Possibly in a physical pair with NGC 5004, which has a similar distance.

Historical Identification: Per Dreyer, IC 4211 (= Wolf list V # 236, 1860 RA 13 04 28, NPD 52 04.7) is "considerably faint, small, extended 315°, brighter middle". The position precesses to RA 13 10 56.4, Dec +37 10 33, right on the star listed above. Even more convincingly, per Corwin a print of the original plate shows Wolf's mark right on the star, so the identification is certain. (Because of the position angle in the description, a fainter star to the northwest is sometimes included in the IC "object", but Corwin states it is not visible on a print of Wolf's plate, so the IC entry applies only to the brighter star.)

Historical Identification: Per Dreyer, IC 4212 (= DeLisle Stewart #373, 1860 RA 13 05 14, NPD 96 01) is "extremely faint, extremely small, considerably extended 20°". The position precesses to RA 13 12 30.5, Dec -06 45 41, but there is nothing there or anywhere near there. However, per Corwin this is one of four nebulae found by Stewart on Harvard plate A3776, all of which have poor positions; and although the position of Stewart's #373 would have to be very poor for it to be the galaxy listed above, that is the nearest object he could have seen on the plate, and its bright central bar perfectly fits the description. So although PGC 45845 is 15 arcmin south southwest of Stewart's position, its identification as IC 4212 is reasonably certain.
Physical Information: Based on a recessional velocity of 1475 km/sec, IC 4212 is about 70 million light years away, in fair agreement with a redshift-independent distance estimate of 85 million light years. Given that and its apparent size of 3.0 by 2.2 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4213 (= Javelle #1237, 1860 RA 13 05 51, NPD 53 35.2) is "faint, large, very much extended north-south, gradually very little brighter middle". The position precesses to RA 13 12 20.9, Dec +35 40 08, just over 2 arcmin east of the galaxy listed above, but there is nothing else nearby, and its appearance so perfectly fits the description that the identity is certain.
Physical Information: Based on a recessional velocity of 815 km/sec, IC 4213 is about 40 million light years away, in fair agreement with redshift-independent distance estimates of 55 to 70 million light years, since for such small radial velocities peculiar (non-Hubble expansion) velocities can substantially affect the calculation. Assuming a median probable distance of about 55 million light years, its apparent size of about 2.6 by 0.4 arcmin corresponds to about 40 thousand light years.

Historical Identification: Per Dreyer, IC 4214 (= Swift list XI (#152), 1860 RA 13 08 57, NPD 121 21.1) is "pretty bright, pretty small, round, 9th magnitude star to southeast" (Swift's paper adds "northwestern of 2", the other being IC 4219, but as his positions show, it is actually the "southwestern of 2"). The position precesses to RA 13 16 43.4, Dec -32 05 32, but there is nothing there, or anywhere near there. However, the galaxy listed above lies exactly 1 minute of time to the east, suggesting a common error in using a setting circle to measure positions (which was Swift's method of measuring positions), and the star on the galaxy's southeastern border appears to make the identification certain. (As it happens, this is one of three galaxies observed by Swift on the same night (the others being IC 4219 and 4233), all of which have the same error in right ascension. This suggests that the right ascension setting circle on Swift's telescope was mis-set by a minute of time at the start of his observing session.)
Physical Information: Based on a recessional velocity of 2310 km/sec, IC 4214 is about 110 million light years away, in reasonable agreement with a redshift-independent distance estimate of 90 million light years. Given that and its apparent size of 3.2 by 2.1 arcmin, it is about 100 thousand light years across.

Historical Identification: Per Dreyer, IC 4215 (= Javelle #1238, 1860 RA 13 09 34, NPD 63 51.4) is "faint, small, extended 210°". The position precesses to RA 13 16 16.0, Dec +25 24 11, right on the galaxy, so the identification is certain.
Physical Information: Based on a recessional velocity of 3910 km/sec, IC 4215 is about 180 million light years away. Given that and its apparent size of 1.6 by 0.3 arcmin, it is about 85 thousand light years across.

Historical Identification: Per Dreyer, IC 4216 (= DeLisle Stewart #374, 1860 RA 13 09 42, NPD 100 02) is "very faint, considerably large, considerably extended 40°". The position precesses to RA 13 17 03.1, Dec -10 46 24, on the southeastern edge of the galaxy, so the identification is certain.
Physical Information: Based on a recessional velocity of 2845 km/sec, IC 4216 is about 130 million light years away. Given that and its apparent size of 2.0 by 0.75 arcmin, it is about 75 thousand light years across.

Historical Identification: Per Dreyer, IC 4217 (= DeLisle Stewart #376, 1860 RA 13 09 48, NPD 102 24) is "extremely faint, extremely small, round". The position precesses to RA 13 17 11.7, Dec -13 08 23, only an arcmin northwest of the galaxy listed above, and there is nothing else nearby, so the identification is essentially certain.
Physical Information: Based on a recessional velocity of 6900 km/sec, IC 4217 is about 320 million light years away. Given that and its apparent size of 0.75 by 0.65 arcmin, it is about 70 thousand light years across.

Historical Identification: Per Dreyer, IC 4218 (= DeLisle Stewart #375, 1860 RA 13 09 51, NPD 91 31) is "extremely faint, extremely small, considerably extended 170°; suspected". The position precesses to RA 13 17 03.2, Dec -02 15 23, right on the galaxy listed above, and its appearance matches the description, so the identity is certain.
Physical Information: Based on a recessional velocity of 5795 km/sec, IC 4218 is about 270 million light years away, in good agreement with redshift-independent distance estimates of 265 to 315 million light years. Given that and its apparent size of 1.15 by 0.4 arcmin, it is about 100 thousand light years across. A Seyfert galaxy (type Sy 1.2).

Historical Identification: Per Dreyer, IC 4219 (= Swift list XI (#153), 1860 RA 13 09 52, NPD 120 55.1) is "most extremely faint, pretty large, round, 9th magnitude star to southwest" (Swift's paper adds "southeastern of 2", the other being IC 4214, but as his positions show, it is actually the "northeastern of 2"). The position precesses to RA 13 17 38.2, Dec -31 39 28, but there is nothing there. However, as noted in the entry for IC 4214, it appears that Swift probably made a minute of time error in adjusting his right ascension setting circle on the night in question, and adding that minute of time to the IC2 right ascension places us only 2.4 arcmin to the southeast of the galaxy listed above; the presence of an appropriately bright star to the southwest of the galaxy then makes its identification as IC 4219 reasonably certain.
Physical Information: Based on a recessional velocity of 3655 km/sec, IC 4219 is about 170 million light years away. Given that and its apparent size of 1.2 by 1.15 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4220 (= DeLisle Stewart #377, 1860 RA 13 10 29, NPD 102 52) is "extremely faint, extremely small, considerably extended 130°". The position precesses to RA 13 17 53.3, Dec -13 36 21, right on the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 6385 km/sec, IC 4220 is about 295 million light years away. Given that and its apparent size of 0.9 by 0.65 arcmin, it is about 75 thousand light years across.

Historical Identification: Per Dreyer, IC 4221 (= DeLisle Stewart #378, 1860 RA 13 10 59, NPD 103 53) is "considerably faint, small, much extended 165°, considerably brighter middle". The position precesses to RA 13 18 24.5, Dec -14 37 19, only 1.5 arcmin southwest of the galaxy listed above, and its appearance fits the description, so the identification is certain.
Physical Information: Based on a recessional velocity of 2890 km/sec, IC 4221 is about 135 million light years away. Given that and its apparent size of 1.6 by 0.75 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4222 (= Swift list XI (#154), 1860 RA 13 11 48, NPD 117 41.4) is "most extremely faint, extremely small, round" (Swift's paper adds "(NGC) 5078 near to northeast", which is the key to identifying the object). The position precesses to RA 13 19 30.6, Dec -27 25 39, which lies in a completely stellar field devoid of any nebulae. But just to the southwest of NGC 5078 there is a nebula, IC 879, that lies exactly one degree to the north and a couple of arcmin east of Swift's position for IC 4222; so it is certain that Swift XI-154 is simply a reobservation of IC 879 with a 1 degree error in the declination.
Physical Information: Given the duplicate entry, see IC 879 for anything else.

Historical Identification: Per Dreyer, IC 4223 (= Bigourdan #411, 1860 RA 13 11 55, NPD 81 27) is "extremely faint, small, mottled but not resolved". The position precesses to RA 13 18 56.6, Dec +07 48 44, only an arcmin northeast of the galaxy listed above, and there is nothing else nearby that Bigourdan could have seen, so the identification is essentially certain.
Physical Information: Based on a recessional velocity of 14885 km/sec, a straightforward calculation indicates that IC 4223 is almost 700 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 655 million light years away at the time the light by which we see it was emitted, about 670 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 0.95 by 0.35 arcmin, it is about 180 thousand light years across.

Historical Identification: Per Dreyer, IC 4224 (= DeLisle Stewart #379, 1860 RA 13 11 56±, NPD 91 46±) is "extremely faint, small, considerably extended 110°, suspected". The position precesses to RA 13 19 08.5, Dec -02 30 15, just northeast of the galaxy listed above, and since its appearance matches the description, the identification is certain (actually, for a measurement listed as approximate, the position is unusually accurate).
Physical Information: Based on a recessional velocity of 5540 km/sec, IC 4224 is about 260 million light years away. Given that and its apparent size of 1.0 by 0.45 arcmin, it is about 75 thousand light years across.

Historical Identification: Per Dreyer, IC 4225 (= Javelle #1239, 1860 RA 13 13 29, NPD 57 16.9) is "faint, considerably small, round". The position precesses to RA 13 20 00.3, Dec +31 58 56, right on the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 5440 km/sec, IC 4225 is about 255 million light years away. Given that and its apparent size of 1.45 by 0.35 arcmin, it is about 105 thousand light years across.

Historical Identification: Per Dreyer, IC 4226 (= Javelle #1240, 1860 RA 13 13 59, NPD 57 15.5) is "faint, very small, stellar nucleus". The position precesses to RA 13 20 30.1, Dec +32 00 22, right on the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 5510 km/sec, IC 4226 is about 255 million light years away. Given that and its apparent size of 0.7 by 0.35 arcmin, it is about 50 thousand light years across.

Historical Identification: Per Dreyer, IC 4227 (= Javelle #1241, 1860 RA 13 14 23, NPD 57 05.1) is "faint, small, gradually brighter middle, mottled but not resolved". The position precesses to RA 13 20 53.6, Dec +32 10 47, less than an arcmin south of the galaxy listed above, and there is nothing else nearby so the identification is certain.
Physical Information: Based on a recessional velocity of 6915 km/sec, IC 4227 is about 320 million light years away. Given that and its apparent size of 0.5 by 0.4 arcmin, it is about 45 thousand light years across.

Historical Identification: Per Dreyer, IC 4228 (= Javelle #1242, 1860 RA 13 14 52, NPD 63 45.1) is "faint, small, mottled but not resolved". The position precesses to RA 13 21 31.9, Dec +25 30 50, on the western periphery of the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 10140 km/sec, a straightforward calculation indicates that IC 4228 is about 470 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 455 million light years away at the time the light by which we see it was emitted, about 460 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 0.7 by 0.45 arcmin, it is about 90 thousand light years across.

Historical Identification: Per Dreyer, IC 4229 (= DeLisle Stewart #380, 1860 RA 13 15 21, NPD 91 40) is "extremely faint, extremely small, round, suspected". The position precesses to RA 13 22 33.5, Dec -02 24 01, about 2 arcmin northeast of the galaxy listed above, but that is the only nearby nebula, so the identification is reasonably certain.
Physical Information: Based on a recessional velocity of 6960 km/sec, IC 4229 is about 325 million light years away. Given that and its apparent size of 1.0 by 0.75 arcmin, it is about 95 thousand light years across.

Historical Identification: Per Dreyer, IC 4230 (= Javelle #1243, 1860 RA 13 15 22, NPD 62 32.0) is "faint, small, round, nuclear". The position precesses to RA 13 22 00.1, Dec +26 43 58, right on the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 7280 km/sec, IC 4230 is about 340 million light years away, in good agreement with redshift-independent distance estimates of 275 to 350 million light years. Given that and its apparent size of 1.2 by 0.3 arcmin, it is about 120 thousand light years across.

Historical Identification: Per Dreyer, IC 4231 (= Frost #1042, 1860 RA 13 15 37, NPD 115 34) is "pretty large, very much extended". The position precesses to RA 13 23 18.2, Dec -26 17 59, only an arcmin east of the galaxy listed above, and its appearance perfectly matches the description, so the identification is certain.
Physical Information: Based on a recessional velocity of 2260 km/sec, IC 4231 is about 105 million light years away, in good agreement with redshift-independent distance estimates of 85 to 115 million light years. Given that and its apparent size of 1.9 by 0.4 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4232 (= Frost #1043, 1860 RA 13 15 49, NPD 115 22) has a "brighter middle, magnitude 14". The position precesses to RA 13 23 30.0, Dec -26 05 59, about 2 arcmin northeast of the galaxy listed above; but there is nothing else nearby and the description fits, so the identification is essentially certain.
Physical Information: Based on a recessional velocity of 9425 km/sec, IC 4232 is about 440 million light years away, in reasonable agreement with widely varying redshift-independent distance estimates of 265 to 610 million light years. Given that and its apparent size of 1.2 by 0.4 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4233 (= Swift list XI (#155), 1860 RA 13 16 12, NPD 119 35.0) is "most extremely faint, pretty small, round, 4 stars to southeast". The position precesses to RA 13 23 59.2, Dec -30 18 57, but there is nothing there. However, as in the case of IC 4214 and IC 4219, which were observed on the same night, there is an appropriate object about a minute of time to the east, namely NGC 5124, which does have (as expressed in Swift's paper) a "trapezium near southeast". So although Swift probably adjusted his setting circle incorrectly on the night in question, resulting in a relatively poor position (and a duplicate listing), the identification is certain.
Physical Information: Given the duplicate entry, see NGC 5124 for anything else.

Historical Identification: Per Dreyer, IC 4234 (= Javelle #1244, 1860 RA 13 16 23, NPD 62 10.2) is "faint, considerably small, round, nuclear, mottled but not resolved". The position precesses to RA 13 23 00.2, Dec +27 05 50, almost an arcmin south of the galaxy listed above, but there is nothing else nearby, so the identification is essentially certain.
Physical Information: Based on a recessional velocity of 10325 km/sec, a straightforward calculation indicates that IC 4234 is about 480 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 460 million light years away at the time the light by which we see it was emitted, about 470 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 0.7 by 0.5 arcmin, it is about 95 thousand light years across.

Historical Identification: Per Dreyer, IC 4235 (= DeLisle Stewart #381, 1860 RA 13 16 29, NPD 102 01) is "extremely faint, very small, round". The position precesses to RA 13 23 53.4, Dec -12 44 56, only a third of an arcmin south of the galaxy listed above, and there is nothing else nearby so the identification seems certain.
Physical Information: Based on a recessional velocity of 5410 km/sec, IC 4235 is about 250 million light years away. Given that and its apparent size of 0.8 by 0.2 arcmin, it is about 60 thousand light years across.

Historical Identification: Per Dreyer, IC 4236 (= Swift list XI (#156), 1860 RA 13 16 32, NPD 83 02.1) is "most extremely faint, pretty small, much extended, very difficult" (Swift's paper adds "in vacancy", and per Corwin, Swift published two papers about this object prior to his "long list", both of which stated it was cE (= considerably extended), so eE (= much extended) appears to be a transcription error). The position precesses to RA 13 23 34.9, Dec +06 13 57, but there is nothing there. However, there is an appropriate object just under 10 arcmin to the north, in a region nearly devoid of notable stars, so it appears that the galaxy listed above is reasonably certain to be what Swift observed. Unfortunately, it also happens to be an object already discovered more than a century earlier, so even though the identification is reasonably certain, it simply results in a duplicate entry.
Physical Information: Given the duplicate entry, see NGC 5118 for anything else.

Historical Identification: Per Dreyer, IC 4237 (= Bigourdan #317, 1860 RA 13 16 57, NPD 110 25) is "very faint, small, little brighter middle, mottled but not resolved". The position precesses to RA 13 24 31.8, Dec -21 08 54, on the southern periphery of the galaxy listed above, so the identification seems certain.
Physical Information: Based on a recessional velocity of 2660 km/sec, IC 4237 is about 125 million light years away, in good agreement with redshift-independent distance estimates of 90 to 150 million light years. Given that and its apparent size of 2.25 by 1.5 arcmin, it is about 80 thousand light years across.

Historical Identification: Per Dreyer, IC 4238 (= Javelle #1245, 1860 RA 13 17 29, NPD 58 20.3) is "faint, very small, diffuse, (NGC) 5131 to northwest". The position precesses to RA 13 24 00.0, Dec +30 55 48, right on the galaxy listed above, and although NGC 5131 is more to the north than northwest, the identification is certain.
Physical Information: Based on a recessional velocity of 6675 km/sec, IC 4238 is about 310 million light years away. Given that and its apparent size of 0.8 by 0.15 arcmin, it is about 70 thousand light years across.

Historical Identification: Per Dreyer, IC 4239 (= Javelle #1246, 1860 RA 13 17 55, NPD 58 18.7) is "faint, considerably small, diffuse". The position precesses to RA 13 24 25.8, Dec +30 57 26, right on the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 14490 km/sec, a straightforward calculation indicates that IC 4239 is about 675 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was almost 640 million light years away at the time the light by which we see it was emitted, almost 655 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). (Note: This is in good agreement with redshift-independent distance estimates of 490 to 800 million light years.) Given that and its apparent size of 0.8 by 0.5 arcmin, it is about 145 thousand light years across.

Historical Identification: Per Dreyer, IC 4240 (= Javelle #1247, 1860 RA 13 17 57, NPD 58 17.6) is "faint, very small, diffuse". The position precesses to 13 24 27.8, Dec +30 58 32, on the eastern edge of the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 6750 km/sec, IC 4240 is about 315 million light years away. Given that and its apparent size of 0.45 by 0.2 arcmin, it is about 40 thousand light years across.

Historical Identification: Per Dreyer, IC 4241 (= Javelle #1248, 1860 RA 13 18 10, NPD 62 32.0) is "faint, small, irregular figure, 12.5 magnitude star attached". The position precesses to RA 13 24 47.0, Dec +26 44 09, right on the galaxy listed above, and the star immediately to its south would undoubtedly have appeared "attached" to Javelle, so the identification is certain.
Physical Information: Based on a recessional velocity of 7000 km/sec, IC 4241 is about 325 million light years away. Given that and its apparent size of 0.55 by 0.5 arcmin, it is about 50 thousand light years across.

Historical Identification: Per Dreyer, IC 4242 (= Javelle #1249, 1860 RA 13 18 11, NPD 58 14.7) is "faint, small, round, nuclear". The position precesses to RA 13 24 41.6, Dec +31 01 27, on the southeastern end of the galaxy listed above, so the identification is certain.
Physical Information: Based on a recessional velocity of 7175 km/sec, IC 4242 is about 335 million light years away. Given that and its apparent size of 0.55 by 0.35 arcmin, it is about 55 thousand light years across.

Historical Identification: Per Dreyer, IC 4243 (= Frost #1044, 1860 RA 13 18 12, NPD 116 54) has a "brighter middle, magnitude 14". The position precesses to RA 13 25 56.1, Dec -27 37 48, about an arcmin east of the galaxy listed above, and its appearance matches the description, so the identification is certain.
Physical Information: Based on the recessional velocity of 11855 km/sec, a straightforward calculation indicates that IC 4243 is about 550 million light years away. However, for objects at such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was almost 530 million light years away at the time the light by which we see it was emitted, almost 540 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 0.75 by 0.55 arcmin, it is about 115 thousand light years across.

Historical Identification: Per Dreyer, IC 4244 (= Javelle #1250, 1860 RA 13 18 22, NPD 62 48.7) is "faint, small, round, gradually brighter middle". The position precesses to RA 13 24 59.3, Dec +26 27 28, less than an arcmin southeast of the galaxy listed above, and there is nothing else nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 7280 km/sec, IC 4244 is about 340 million light years away. Given that and its apparent size of 0.75 by 0.3 arcmin, it is about 75 thousand light years across.

Historical Identification: Per Dreyer, IC 4245 (= Frost #1045, 1860 RA 13 18 24, NPD 115 56) is "one of 2 nebulae with a difference in right ascension of 0.3 arcmin" (of these, IC 4245 would be the western, and IC 4246 the eastern). The position precesses to RA 13 26 06.8, Dec -26 39 48, just under 2 arcmin northeast of a pair of galaxies that perfectly match the description, so the identification of the pair is certain, and as noted above IC 4245 must be the western component (discussed in this entry), and IC 4246 must be the eastern component (discussed immediately following this entry).
Physical Information: Although the images below are crude, there is little doubt that the two galaxies are interacting, and their very similar recessional velocities (9735 km/sec for IC 4245, and 9940 km/sec for IC 4246) does nothing to rebut that interpretation. They must therefore be at the same distance, and it seems most appropriate to use their average recessional velocity to estimate that distance. Based on their 9840 km/sec average recessional velocity, the pair must be about 460 million light years away. Given that and its apparent size of 0.45 by 0.4 arcmin, the western component (IC 4245) must be about 60 thousand light years across, while the 0.75 by 0.4 arcmin apparent size of the eastern component (IC 4246) corresponds to about 100 thousand light years.

Historical Identification: Per Dreyer, IC 4246 (= Frost #1045, 1860 RA 13 18 24, NPD 115 56) is "one of 2 nebulae with a difference in right ascension of 0.3 arcmin" (of these, IC 4245 (which see for images, a discussion of the historical identification, and almost everything else about the pair) would be the western, and IC 4246 the eastern).
Physical Information: As noted in the discussion of IC 4245, IC 4246 has a recessional velocity of 9940 km/sec, an apparent size of 0.75 by 0.4 arcmin, a probable distance of about 460 million light years, and a probable physical size of about 100 thousand light years.

Historical Identification: Per Dreyer, IC 4247 (= Frost #1046, 1860 RA 13 18 53, NPD 119 37) is "small, extended, magnitude 14". The position precesses to RA 13 26 41.4, Dec -30 20 45, about an arcmin northwest of the galaxy listed above, but there is nothing else nearby and its appearance fits the description, so the identification is certain.
Physical Information: IC 4247's recessional velocity of 275 km/sec is too small (in comparison to non-Hubble expansion peculiar velocities) to provide a useful indication of its distance, which must be determined from redshift-independent distance estimates of 15 to 17 million light years. Using a median distance of 16 million light years, the galaxy's apparent size of 1.5 by 0.65 arcmin corresponds to about 7 thousand light years.

Historical Identification: Per Dreyer, IC 4248 (= Frost #1047, 1860 RA 13 18 59, NPD 119 10) is "faint, spiral, 13th magnitude star in middle". The position precesses to RA 13 26 46.8, Dec -29 53 45, about an arcmin due south of the galaxy above, which perfectly matches the description (though the 13th magnitude "star" may actually be part of the galaxy), so the identification is certain.
Physical Information: Based on a recessional velocity of 4105 km/sec, IC 4248 is about 200 million light years away. Given that and its apparent size of 1.2 by 0.9 arcmin, it is about 70 thousand light years across.

Historical Identification: Per Dreyer, IC 4249 (= Frost #1048, 1860 RA 13 19 30, NPD 117 13) is "very faint, brighter middle, magnitude 13, near bright star". The position precesses to 13 27 15.1, Dec -27 56 43, about 2 arcmin northeast of the galaxy listed above, but aside from the fact that there is nothing else nearby, the star on the galaxy's eastern edge makes the identification certain.
Physical Information: Based on a recessional velocity of 2025 km/sec, IC 4249 is about 95 million light years away. Given that and its apparent size of 1.2 by 0.35 arcmin, it is about 35 thousand light years across.