Historical Identification: Per Dreyer, IC 300 (Swift list VIII (#23), 1860 RA 03 04 52, NPD 48 04.9) is "extremely faint, small, round, 9th magnitude star to southwest, northwestern of 2", the other being IC 301. The position precesses to RA 03 14 07.0, Dec +42 26 47, a couple of arcmin northwest of the galaxy listed above. The description seems more or less suitable and the relative position of IC 301 is correct, so the identification is reasonably certain; but Corwin notes that Swift's description of the starfield could have been better, and feels that a more suitable candidate may eventually surface.
CORRECTION TO THE ABOVE IDENTIFICATION: Thanks to a suggestion by Steve Gottlieb, it is now almost certain that IC 300 is actually PGC 11982, with a one minute error in the right ascension. As a result, the physical information and images below and the description above will be moved to a new entry, immediately following this one; and this entry will be changed to explain and reflect the new identification. I am currently working on problems with another entry, so it may be a day or so before I can make these changes; hence this temporary note.
Physical Information: Apparent size of about 0.5 by 0.45 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 301 (Swift list VIII (#24), 1860 RA 03 05 27, NPD 48 17.9) is "extremely faint, pretty small, round, southeastern of 2", the other being IC 300.
Physical Information: Apparent size of about 1.0 by 0.9 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 302 (Javelle #581, 1860 RA 03 05 30, NPD 85 49.4) is "pretty faint, pretty small, round, very small nucleus".
Physical Information: Apparent size of about 2.3 by 2.2 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 303 (Javelle #582, 1860 RA 03 05 59, NPD 102 13.3) is "extremely faint, extremely small, stellar".
Physical Information: Apparent size of about 0.4 by 0.25 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 304 (Burnham, 1860 RA 03 06 06, NPD 52 38.6) is "very faint, star 76 arcsec to southeast, northwestern of 2", the other being IC 305.
Physical Information: Possibly interacting with IC 305? Apparent size of about 1.0 by 0.5 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 305 (Burnham, 1860 RA 03 06 08, NPD 52 39.9) is "very faint, star 49 arcsec to northeast".
Physical Information: Possibly interacting with IC 304? Apparent size of about 0.55 by 0.45 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 306 (Javelle #583, 1860 RA 03 06 18, NPD 102 14.8) is "extremely faint, small, round, difficult".
Physical Information: Apparent size of about 0.55 by 0.3 arcmin for the main galaxy; with its northern extension, it is about 0.55 by 0.55 arcmin (both sizes from the images below). Its apparent companion is magnitude 16(?) spiral galaxy (type Sc?) PGC 962632 (RA 03 12 58.9, Dec -11 42 40); nothing save its size (about 0.3 by 0.25 arcmin, also from the images below) available, so whether the pair is a physical or optical double is unknown.

Historical Identification: Per Dreyer, IC 307 (Javelle #108, 1860 RA 03 06 37, NPD 90 44.1) is "pretty bright, very small, mottled but not resolved".
Physical Information: Apparent size of about 1.8 by 0.65 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 308 (Swift list VIII (#25), 1860 RA 03 06 48, NPD 49 20.6) is "extremely faint, pretty small, irregularly round, mottled but not resolved?"
Physical Information: Apparent size of about 1.05 by 1.05 arcmin (from the images below). Vr 6290 km/sec.

Historical Identification: Per Dreyer, IC 309 (Swift list VIII (#26), 1860 RA 03 06 52, NPD 49 43.0) is "most extremely faint, pretty small, round, between 2 stars".
Physical Information: Apparent size of about 1.0 by 0.95 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 310 (Swift list VIII (#28), 1860 RA 03 07 32, NPD 49 11.2) is "very faint, pretty small, round, (NGC) 1259 and 1260 near".
Discovery Notes: Listed in Swift's paper as discovered by his son, Edward.
Physical Information: Apparent size of about 1.25 by 1.15 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 311 (Swift list VIII (#27), 1860 RA 03 07 34, NPD 50 30.8) is "extremely faint, pretty small, irregularly round, between 2 stars, very faint star very close to east".
Physical Information: Apparent size of about 1.4 by 1.05 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 312 (Swift list VIII (#29), 1860 RA 03 08 54, NPD 48 46.5) is "most extremely faint, pretty small, round, nearly between 2 stars". The position precesses to RA 03 18 07.9, Dec 41 44 34, less than 0.7 arcmin due south of the galaxy listed above, the description fits and there is nothing comparable nearby, so the identification is certain.
February 2017 Identification as NGC 1265: As discussed in the entry for NGC 1265, which was previously misidentified as PGC 12287, Bigourdan's observation was actually a prior discovery of what became IC 312. As a result, NGC 1265 and IC 312 are duplicate entries.
Physical Information: Given the duplicate entry, see NGC 1265 for anything else.

Historical Identification: Per Dreyer, IC 313 (Swift list VIII (#33), 1860 RA 03 11 42, NPD 48 36.8) is "most extremely faint, very small, round, close double star near to south".
Physical Information: Apparent size of about 1.05 by 0.85 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 314 (Bigourdan #140, 1860 RA 03 11 45, NPD 92 29) is "a 13th magnitude star in a very faint, small nebula". The position precesses to RA 03 18 49.8, Dec -01 58 12, right on the galaxy, so the identity is certain. The duplicate entry was the result of an 11 seconds of time error in Swift's right ascension, but by the time Bigourdan published his "big list" (a summary of all his discoveries) he had realized that his #140 must be the same as NGC 1289 (which see for anything else), and stated as much; so the duplication has been known for more than a century.

Historical Identification: Per Dreyer, IC 315 (Javelle #584, 1860 RA 03 11 50, NPD 86 29.4) is "very faint, small, diffuse, a very little brighter middle".
Physical Information: Apparent size of about 0.8 by 0.35 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 316 (Swift list VIII (#34), 1860 RA 03 12 09, NPD 48 34.6) is "most extremely faint, pretty small, round".
Physical Information: The two galaxies are surrounded by an extensive region of space filled with stars and gas thrown outwards as a result of their interaction. PGC 12576 is a distorted edge-on spiral galaxy, while PGC 12578 is a bi-nuclear peculiar galaxy. The apparent size of the brighter central portion of PGC 12576 is about 0.4 by 0.1 arcmin, while the similar region for PGC 12578 is about 0.25 by 0.2 arcmin (all preceding and following apparent sizes from the images below). The extended cloud of material surrounding both galaxies covers a region about 1.5 by 1.35 arcmin in size.

Historical Identification: Per Dreyer, IC 317 (Javelle #109, 1860 RA 03 12 18, NPD 103 15.5) is "very faint, pretty large, round".
Physical Information: Apparent size of about 0.75 by 0.6 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 318 (Javelle #110, 1860 RA 03 14 11, NPD 105 04.4) is "faint, small, diffuse, a little brighter middle".
Physical Information: Apparent size of about 0.85 by 0.35 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 319 (Bigourdan #141, 1860 RA 03 14 13, NPD 49 06) is "stellar, = 13th magnitude star". The position precesses to RA 03 23 28.0, Dec +41 24 15, almost exactly on a faint galaxy, PGC 2180624, that was long identified as Bigourdan's object. However, although the galaxy is clearly visible on photographs of the region, it would have looked much fainter to a visual observer than stars of comparable brightness, since the light of a star is concentrated in nearly a single point, while the light of a nebula is spread out; and Bigourdan probably couldn't see the galaxy, and certainly wouldn't have described it in the way he did. (Despite that, since it was long misidentified as IC 319, the galaxy is discussed immediately below). That makes the 14th-magnitude star a few arcsec southeast of the galaxy the most obvious candidate for IC 319, and it is listed as such in some references. But as noted by Corwin and Thomson, Bigourdan's detailed notes provide the relative positions of a number of nearby stellar objects (such as the 11th-magnitude double star 20 seconds east of his #141) that do not fit the star field if either the galaxy or the star to its southeast is IC 319. Instead, they point almost unequivocally to the star listed above.

Physical Information: Based on a recessional velocity of 4625 km/sec (and H₀ = 70 km/sec/Mpc), PGC 2180624 is about 215 million light years away. Given that and its apparent size of about 0.65 by 0.55 arcmin (from the image below), it is about 40 thousand light years across.

Historical Identification: Per Dreyer, IC 320 (Swift list VIII (#35), 1860 RA 03 16 42, NPD 49 42.5) is "extremely faint, pretty small, round, very faint star close to west".
Physical Information: Apparent size of about 1.5 by 1.3 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 321 (Javelle #111, 1860 RA 03 17 58, NPD 105 29.0) is "pretty bright, very small, round".
Physical Information: Apparent size of about 0.85 by 0.75 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 322 (Javelle #585, 1860 RA 03 18 42, NPD 86 49.1) is "very faint, pretty large, a very little brighter middle, difficult".
Physical Information: Apparent size of about 0.75 by 0.7 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 323 (Swift list VIII (#36), 1860 RA 03 20 11, NPD 48 37.6) is "extremely faint, pretty small, round, western of 2", the other being NGC 1334. Swift's Catalog No. 8 note adds "star very near". The position precesses to RA 03 29 30.8, Dec +41 51 42, just south of 11th-magnitude TYC 2869-1992-1, so it is presumably the "star very near", and IC 323 is something very close to that star; but there is nothing there save for scattered stars, so some of those must be what Swift recorded. Per Corwin, Swift could have easily mistaken the grouping listed above for a nebula, and there appears to be general agreement that this identification is the one that makes the most sense.
Physical Information:

Historical Identification: Per Dreyer, IC 324 (Bigourdan #142, 1860 RA 03 20 16, NPD 111 51) is "faint, pretty small, diffuse, brighter middle". The position precesses to RA 03 26 28.8, Dec -21 21 28, right on the galaxy, so the identification is certain. Per Corwin the duplicate listing was caused by Herschel's position being very poor; in fact so poor that when Dreyer published his analysis of Herschel's papers in 1912 and realized that NGC 1331 must be the same as IC 324 he recommended using the IC designation instead of the NGC one. However, it is traditional to use NGC designations when available, so current usage is to call the galaxy NGC 1331 (which see for anything else), and to ignore Dreyer's recommendation.

Historical Identification: Per Dreyer, IC 325 (Javelle #112, 1860 RA 03 23 58, NPD 97 31.8) is "very faint, small, round, a very little brighter middle".
Physical Information: Apparent size of about 0.8 by 0.7 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 326 (Javelle #113, 1860 RA 03 24 05, NPD 104 54.6) is "very faint, pretty large, extended north-south".
Physical Information: Apparent size of about 1.2 by 0.8 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 327 (Javelle #586, 1860 RA 03 24 38, NPD 105 10.7) is "extremely faint, very small, diffuse, very difficult".
Physical Information: Apparent size of about 0.75 by 0.4 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 328 (Javelle #114, 1860 RA 03 24 40, NPD 105 07.3) is "very faint, extremely small, round".
Physical Information: Apparent size of about 0.65 by 0.45 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 329 (Javelle #115, 1860 RA 03 24 51, NPD 90 11.4) is "faint, very small, round, a little brighter middle".
Physical Information: Apparent size of about 0.95 by 0.35 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 330 (Javelle #116, 1860 RA 03 24 58, NPD 90 06.8) is "faint, very small, round, a little brighter middle".
Physical Information: Apparent size of about 1.15 by 0.35 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 331 (Javelle #117, 1860 RA 03 25 09, NPD 90 11.2) is "a 13th magnitude star in a nebula".
Physical Information: Apparent size of about 1.0 by 0.9 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 332 (Javelle #587, 1860 RA 03 25 26, NPD 89 04.8) is "faint, very small, round, suddenly brighter middle".
Physical Information: Apparent size of about 0.95 by 0.5 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 333 (Bigourdan #143, 1860 RA 03 27 06, NPD 95 35) is "extremely faint, 8.8 magnitude star 4 arcmin to northeast", the star being identified by Bigourdan as BD-5 687 (= HD 22171). The position precesses to RA 03 34 02.4, Dec -05 06 37 (whence the position above), but although HD 22171 is indeed 4 arcmin northeast of the position (confirming the supposed observation), there is nothing near Bigourdan's position save for a 17th magnitude star. But as noted by Corwin, Bigourdan only observed the supposed object once and only 'suspected' its existence, so it is almost certainly a nonexistent object.

Historical Identification: Per Dreyer, IC 334 (Denning, 1860 RA 03 27 31, NPD 13 48) is "pretty bright, small, 13th magnitude star involved on southeast".
Physical Information: Apparent size of about 3.95 by 3.35 arcmin (including extensive outer regions, as shown in the images below). Almost certainly a starburst galaxy, and/or the result of a galactic collision.

Historical Identification: Per Dreyer, IC 335 (Swift list VII (#8), 1860 RA 03 29 35, NPD 124 55.0) is "pretty faint, pretty small, extremely extended east-west". The position precesses to RA 03 35 01.7, Dec -34 26 54, about 30 seconds of time west of the only nearby galaxy, whose appearance so perfectly fits the description that there is no doubt of the identity despite the error in the position. (See IC 1963 for a discussion of the double listing.)
Physical Information: Based on a recessional velocity of 1620 km/sec (and H₀ = 70 km/sec/Mpc), IC 335 is about 75 million light years away, in "reasonable" agreement with widely varying redshift-independent distance estimates of 30 to 70 million light years. It is thought to be a member of the Fornax Galaxy Cluster, and if so is actually about 60 million light years away. Assuming that to be correct, its apparent size of about 1.9 by 0.3 arcmin (from the HST image below) corresponds to about 30 to 35 thousand light years. If it is actually 75 million light years away (and just beyond or on the far side of the Fornax Cluster), it is about 40 to 45 thousand light years across.

Historical Identification: Per Dreyer, IC 336 (Barnard [A.N. N^o] (3253), 1860 RA 03 30±, NPD 67) is "very faint, most extremely large, very diffuse". A.N. 3253 refers to a note and finding chart published by Barnard in the Astronomische Nachricten of that number; unfortunately the finding chart does not show the nebulosities, just stars and a coordinate grid, but a later publication, partially reproduced below, does show many of the nebulosities; also see the IC2 note above). Dreyer's position precesses to RA 03 38 14.9, Dec +23 27 48. Ordinary images show absolutely nothing in this area, and even normal (relatively minor) digital enhancements in brightness and contrast only hint at what might be there; but Barnard's discovery was made by exposing a plate over a period of two days and more than 10 hours, grossly overexposing brighter regions while revealing extremely faint diffuse nebulosities. As the maximally enhanced photomosaic shows, the region is filled with such nebulosity; the only question is which nebulosity corresponds to one of the IC numbers assigned by Dreyer to various smudges on Burnham's drawing. Per Corwin, this is one of several extremely faint diffuse emission and reflection nebulae attributed to Barnard in this region, including IC 336, 341, 353, 354 and 360, but although Barnard did the sketch showing the nebulae, Dreyer chose which ones to add to the IC, and estimated their position from Barnard's finding chart and sketch. Some of the IC objects correspond to obvious smudges on Barnard's sketch, but others do not, so it is hard to understand Dreyer's choices. In the case of IC 336, there is a notable smudge on Barnard's drawing at the position used by Dreyer. The modern position of IC 336 was estimated from a comparison of Dreyer's position, the starfield in the drawing and the actual sky, and the suitably rounded result (corresponding to the rough position given in the IC) stated in the description line for this entry was used as the center of the images shown below. Dreyer's position is well within the 30 arcmin wide nebulosity near the center of the enhanced image, so it should be IC 336. (Note: The spectacular results of the extreme digital enhancement used for the maximally enhanced photomosaic below are atypical. Differences in the brightness and contrast of the original plates scanned for the Digitized Sky Survey, and for that matter, differences in sky conditions and digital exposures used for the Sloan Digital Sky Survey usually produce obvious boundary effects running along geometric lines. The lack of any geometric boundary effects in this region is remarkable, and gives the enhanced image a veracity that most such images cannot match.)

Historical Identification: Per Dreyer, IC 337 (Swift list IX (#12), 1860 RA 03 30 12, NPD 97 11.2) is "most extremely faint, pretty large, 3 stars near" (Swift's Catalogue No. 9 note specifies "trapezium with 3 stars"). The position precesses to RA 03 37 03.9, Dec -06 43 19 (whence the position above), but there is nothing there. PGC 13308, a low-brightness galaxy a little over a minute of time due west seems an attractive possibility because Swift's declinations were generally more accurate than his right ascensions (and Steinicke, for one, assumes that PGC 13308 is indeed IC 337), but Corwin says it almost certainly has too low a surface brightness for Swift to have seen it. He adds that the brighter galaxy PGC 145722 could have been seen by Swift, but is considerably off in both right ascension and declination, and in any event neither object makes a trapezium with any of the stars near it. So it seems most likely that Swift's IX-12 must either be lost or never existed. Still, the PGC objects mentioned as (admittedly unlikely) candidates are discussed immediately below, just in case there is ever any reason to think that one of them might earn the IC entry after all.

Historical Identification: (See IC 337 for a discussion of this object's relevance to that entry.)
Physical Information: Based on a recessional velocity of 3085 km/sec (and H₀ = 70 km/sec/Mpc), PGC 13308 is about 140 to 145 million light years away. Given that and its apparent size of about 1.65 by 1.15 arcmin (from the images below), it is about 70 thousand light years across. One of the galaxy's distorted arms appears to reach for PGC 1029806 (the small galaxy to its north northwest), and if that is a physical companion it may be responsible for PGC 13308's distorted appearance; but since almost nothing is known about the smaller object that can only be treated as speculation.

Historical Identification: (See IC 337 for a discussion of this object's relevance to that entry.)
Physical Information: Apparent size of about 0.95 by 0.6 arcmin (from the images below)

Historical Identification: Per Dreyer, IC 338 (Javelle #588, 1860 RA 03 30 21, NPD 87 19.6) is "very faint, small, diffuse, very faint star close" (Javelle's paper adds "30 arcsec diameter").
Erratum: Steinicke inadvertently switched identifications for IC 338 and IC 340, misidentifying IC 338 as Javelle #118 and IC 340 as Javelle #588; Dreyer's entries are correct.
Physical Information: Apparent size of about 0.85 by 0.65 arcmin (from the images below). The overall form of the galaxy appears to support its classification as type Sc, but its nucleus is unusually large and bright for that class; so it may be a starburst galaxy.

Historical Identification: Per Dreyer, IC 339 (Ormond Stone (#144), 1860 RA 03 31 47, NPD 108 50.5) is "extremely faint, extremely small, stellar nucleus". The position precesses to RA 03 38 06.4, Dec -18 22 50, about an arcmin northeast of the star listed above and there is nothing else nearby, so given the IC description the identification with the star seems certain.

Historical Identification: Per Dreyer, IC 340 (Javelle #118, 1860 RA 03 32 56, NPD 103 34.4) is "faint, pretty small, extended east-west, 14th magnitude star at end" (Javelle's paper indicates an elongation of 45 arcsec.)
Erratum: Steinicke inadvertently switched identifications for IC 338 and IC 340, misidentifying IC 338 as Javelle #118 and IC 340 as Javelle #588; Dreyer's entries are correct.
Physical Information: Apparent size of about 1.5 by 0.5 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 341 (Barnard [A.N. N^o] (#3253), 1860 RA 03 33±, NPD 68 30±) is "very faint, most extremely large, very diffuse" (A.N. 3253 refers to a note and finding chart published by Barnard in the Astronomische Nachricten of that number; unfortunately the finding chart does not show the nebulosities, just stars and a coordinate grid, but a later publication, partially reproduced below, does show many of the nebulosities; also see the IC2 note above the entry for IC 336). Dreyer's position precesses to RA 03 41 10.8, Dec +21 57 19, a few arcmin east of HD 22637, in a region where Barnard drew a relatively bright nebulosity. As the images below show, there is a perfectly matching nebulosity in essentially the same place as Dreyer's position (the center of the nebulosity is only a tenth of a degree north of Dreyer's position, which is a small error, considering the 25 by 12 arcmin apparent size of the nebula and the small scale of Barnard's drawing), so the identity is certain. A rounded-off value for the position (corresponding to the rough position given in the IC) is stated in the description line for this entry, and used as the center of the images shown below. As in the case of IC 336, normal or minimally digitally enhanced images of the area only hint at what might be there; but Barnard's discovery was made by exposing a plate over a period of two days and more than 10 hours, grossly overexposing brighter regions while revealing extremely faint diffuse nebulosities. As the maximally enhanced photomosaic shows, the region is filled with such nebulosity; the only question might be which nebulosity corresponds to one of the IC numbers assigned by Dreyer to various smudges on Burnham's drawing (per Corwin, this is one of several extremely faint diffuse emission and reflection nebulae discovered by Barnard in this region, including IC 336, 341, 353, 354 and 360). But as noted above, in this case Barnard's drawing and the images below so clearly show the nebulosity in question that there is no doubt of the identification: IC 341 is the nebulous region at the center of the images. (Steinicke states 135 arcmin apparent size.)

Almost all astronomical images, whether taken on physical plates as in the past, or as digital images as is usually the case nowadays, have defects or artifacts that require the combination of multiple images and/or considerable 'astro-brushing' to produce the apparently flawless images displayed in textbooks and online. At the end of the discussion of IC 336 it is pointed out that geometric boundary effects are to be expected in photomosaics of digitized images. In that case the area in question has a remarkable freedom from such effects, and apparently represents an accurate view of the region; but in the case of IC 341 a 2-degree wide maximally enhanced image clearly shows a nearly vertical boundary effect on the left side of the image and a nearly horizontal one near the top of the image. In many parts of the sky even the original DSS and SDSS images display such artifacts, without any exaggeration by digital enhancements; instead, digital editing is required to try to minimize such effects. For this entry I have not had to do anything to minimize boundary effects, since they do not affect the area close to IC 341; but I have "swept them under the rug" by reducing the field of view (to 1.5 degrees for the 'normal' image and 1.2 degrees for the 'enhanced' version), moving them nearer to or outside the edge of the field of view. Such editing is considered perfectly ethical and desirable as long as it is done carefully and without any effort to falsify the reality behind the image.

Historical Identification: Per Dreyer, IC 342 (Denning, 1860 RA 03 33 20, NPD 22 21) is "pretty bright, very small, 12th magnitude star close to north". The position precesses to RA 03 46 47.3, Dec +68 05 49, almost dead center on the nucleus of the galaxy, so the identification is certain.
Discovery Notes: Per Steinicke, Barnard recorded this object in the Lick Observatory logbook (reference S36) on the date shown above, but never published the observation, hence its absence in Dreyer's IC entry.
Nickname Note: As noted below, this galaxy lies directly behind the plane of the Milky Way galaxy, and is therefore substantially obscured by clouds of dust in our galaxy; so though it is visible with a telescope, it is far fainter than it would be if it were in any other part of the sky, so though not completely hidden from our view, it is sufficiently obscured to warrant its nickname.
Physical Information: IC 342 is relatively close to our Local Group, being part of the Maffei 1 Group. The brighter members of that group of galaxies (IC 342 and Maffei 1) would be among the most spectacular objects in the sky if they weren't obscured by gas and dust in the plane of our galaxy. As it is, they are hard to see, Maffei 1 not even being noticed until 1968, and Denning's note about IC 342 being "very small" indicating that its fainter outer regions were beyond the reach of his telescope, and all that he could see was the bright core (which marks it as a Seyfert galaxy, type Sy 2). IC 342's recessional velocity of 31 km/sec is far too small to provide any indication of its distance (at small distances, the random or "peculiar" velocities of galaxies relative to their neighbors are much larger than the Hubble expansion velocity), but redshift-independent distance estimates suggest that it is between 8 and 12 million light years away. Given that and its apparent size of about 21.5 by 18 arcmin (from the images below), the galaxy is about 60 to 65 thousand light years across.

Historical Identification: Per Dreyer, IC 343 (Ormond Stone (#163), 1860 RA 03 33 48, NPD 108 53.9) is "extremely faint, very small, a little extended 90°, diffuse".
Discovery Notes: Although Dreyer credits Stone as the author of the paper involved, the paper states that Muller was the actual observer.
Physical Information: Based on a recessional velocity of 1840 km/sec (and H₀ = 70 km/sec/Mpc), IC 343 is about 85 million light years away, in good agreement with redshift-independent distance estimates of 85 to 100 million light years. Given that and its apparent size of about 1.7 by 0.8 arcmin (from the images below), it is about 40 to 45 thousand light years across.

Historical Identification: Per Dreyer, IC 344 (h 305 = Swift list IX (#13), 1860 RA 03 34 34, NPD 95 07.0) is "most extremely faint, pretty large, round, II 455 to east", h 305 being GC 756 = (JH) 305, and (WH) II 455 being NGC 1417
Discovery Notes: Discuss Herschel's observation and Dreyer's failure to include it in the NGC, and Swift's as well (pretty accurate, and stated as being on a line with NGC 1417 and 1418). (Perhaps Herschel was uncertain about the object, but Swift's observation made Herschel's observation seem more certain?)
Physical Information: Apparent size of about 0.75 by 0.35 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 345 (Ormond Stone (#168), 1860 RA 03 34 50, NPD 108 46.0) is "extremely faint, very small, irregularly round, gradually brighter middle". The position precesses to RA 03 41 09.2, Dec -18 18 50, right on the galaxy, so the identification is certain.
Physical Information: Apparent size of about 0.85 by 0.75 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 346 (Ormond Stone (actually Muller #171), 1860 RA 03 35 06, NPD 108 49.4) is "very faint, extremely small". In the notes for the Second Index Catalog Dreyer adds "The place and description should be (1860 RA) 03 35 26, (NPD) 108 43.0), extremely faint, pretty large, extended 80°, diffuse (my mistake). Is no doubt identical with Swift (list) XI #60: (1860 RA) 03 35 13, (NPD) 108 39.8)."
 The position given in the Second IC corresponds exactly to Muller's #171, as shown in parentheses in Dreyer's entry, and indicated by giving Muller credit for the discovery at the start of this entry. It differs by only 0.3 seconds of time in RA and 20 arcsec in Dec from Swift's position for his list XI #60, so Dreyer's supposition that the two observations were of the same object is almost certainly correct. The corrected position precesses to RA 03 41 45.2, Dec -18 15 56, which lies within the eastern rim of the galaxy listed above, the description is a good fit and there is nothing else nearby, so the identification is certain. The only question is what Stone observed, since he also observed something (his #151) in the same region; but that is dealt with below.
Discovery Notes: (1) Though Dreyer gives credit to Stone as author of the paper in question, the paper shows that Muller observed the object. (2) Steinicke lists the discovery date as Oct 22, 1887, but Stone lists it as 1887.806, which (as noted by Corwin) corresponds to Oct 21; so I have changed the date to reflect that.
Physical Information: Based on a recessional velocity of 2085 km/sec (and H₀ = 70 km/sec/Mpc), PGC 13575 is about 95 to 100 million light years away. Given that and its apparent size of about 1.9 by 1.45 arcmin (from the images below), it is about 50 to 55 thousand light years across.

The following was part of the entry for IC 346, but now belongs (if anywhere) to the following entry; so it is placed here while I work on correcting the entry below:
The position precesses to RA 03 41 24.9, Dec -18 22 17, but there is nothing there save for some faint stars. What Stone observed is discussed immediately following this entry but what object should be identified with IC 346 is based on a correction in the second IC: "The place and description should be (1860 RA 03 35 26, NPD 108 43.0), extremely faint, pretty large, extended 80°, diffuse (my [Dreyer's] mistake). Is no doubt identical with Swift list XI #60 (1860 RA 03 35 13, NPD 108 39.8).". The position precesses to RA 03 41 45.2, Dec -18 15 56, which falls right on the galaxy listed above, so the identification is certain. The question then is, what happened to change Dreyer's mind about this listing? The answer is an interesting look into how Dreyer chose to include (or not include) the various reports of "novae" (meaning newly discovered nebulae, not the modern meaning of a particular type of stellar explosion) in the NGC/IC.
 If Dreyer had changed his mind about this entry because of Swift's 1896 observation, he would have created a new entry in the IC2, or simply stated "RA 03 35 13, NPD 108 29.8 (Swift)" as a correction to the position. "The place and description should be" prior to "(my mistake)" suggests that he originally meant to use Muller's observation for IC 346, and inadvertently used Stone's instead. The Leander McCormick Catalog of Southern Galaxies lists five objects in this region, but Dreyer chose to include only four of them in the original IC. The one he left out was Muller's #171, but apparently he meant to leave out Stone's #151, presumably because its description suggested that it was more likely to be a star than a nebula. When he was going through Swift's list XI, he must have noticed that #60 was close to Muller's nova, and belatedly discovered his mistake in the IC entry. So rather than giving Swift's nova a new entry, he used it as a footnote to his correction of the original one.

Historical Identification: As noted in the entry for IC 346 (which see), Dreyer's original entry for IC 346 was for the object recorded by Stone as Leander McCormick #151. In the IC2 Dreyer states that he made a mistake for IC 346, and gives a corrected position and description (though without changing the attribution, presumably because as director of the observatory and author of the paper, "Stone" would have been listed as the reference for the entry anyway). As a result, Stone's observation became a non-entry in the IC; but given its original inclusion in that Catalog, it seems reasonable to wonder what Stone observed. As noted in the entry for IC 346 there is nothing there but scattered stars, so one or more of those must be what Stone observed. The most reasonable identification is the star listed above and shown below, which lies only 0.4 arcmin from Stone's position, and is a good fit to his description of the object as being "14th magnitude, 0.1 arcmin".

Historical Identification: Per Dreyer, IC 347 (Swift list IX (#14), 1860 RA 03 35 36, NPD 94 45.9) is "extremely faint, very small, round, stellar".
Physical Information: Apparent size of about 1.2 by 0.8 arcmin (from the images below).

Historical Identification: Per Dreyer, IC 348 (Safford 70, 1860 RA 03 35 47, NPD 58 16.8) is "pretty bright, very large, very gradually brighter middle". (Per Corwin, Safford's paper included a footnote saying "A loose cluster with nebula", but Dreyer overlooked the footnote, thereby failing to mention the cluster.) The position precesses to RA 03 44 32.9, Dec +32 10 00, right on the cluster, so the identification is certain. (See IC 1985 for a discussion of the double listing.) The object is a cluster of stars whose brightest members are hot, bright bluish Main Sequence stars up to spectral type B5. Clouds of dust in the star-forming region surrounding the cluster scatter the light of stars, producing an even bluer reflection nebula. Both Safford and Barnard noted the brightest part of the nebulosity, and Safford noted the cluster; but neither could have seen the much larger, fainter reflection nebula extending a considerable distance from the cluster.
Physical Information: The cluster contains more than 300 stars of about 2 1/2 million years age (based on the brightest stars still on the Main Sequence), but some stars are still in the process of formation, so star formation is an ongoing process in the region, and many of the stars in the cluster are the subject of intense investigation. (As of March 2013, a close binary pair of protostars, LRLL 54361, is of particular interest, because every 25.34 days it releases a brilliant flash of light presumably related to material surrounding the pair of stars being dumped onto their surfaces when they reach periastron.) Of the stars studied in detail a third have optically thick circumstellar disks similar to the primodial Solar Nebula, and another 20% have thinner, much lower mass disks. Such studies of circumstellar disks in clusters of various ages are expected to yield a better understanding of the dynamics of planet formation. The cluster also contains about thirty confirmed brown dwarfs, with masses as low as 15 to 80 times that of Jupiter. Distance estimates for the cluster range from 950 to 1040 light years, and with some members scattered over a region nearly a degree across, the cluster spans about 15 light years, though the bright central region is only a fifth that size. (Steinicke lists the apparent size of the central region as about 10 arcmin)

Historical Identification: Per Dreyer, IC 349 (Barnard [A.N. N^o] (3018), 1860 RA 03 37 55, NPD 66 41) is "extremely faint, very small, position angle 165°, distance 36 arcsec from Merope".
Physical Information: The Pleiades is an open cluster surrounded by a reflection nebula caused by dust that happens to be in the region the cluster is passing through (the relative motion is about 11 km/sec), and has nothing to do with the dust and gas out of which the Pleiades formed a hundred million years or so ago. IC 349 is a particularly bright knot of reflecting dust near Merope (in fact, the brightest knot in the nebulosity surrounding the cluster). In the DSS images of the Merope nebula (below), Barnard's nebula is completely lost in the glare of the star. However, a PanSTARRS image shows the nebula, and an HST image shows it in detail, revealing the distortion in its shape caused by the pressure exerted on it by the radiation lighting it up. The knot is only 3500 AUs from the star, and its intense radiation is pushing the particles away from the star. The relative motion is bringing the cloud closer to the star, but smaller dust particles are being blown away from the star, causing them to lag behind the net motion of the cloud. Larger particles are less affected by the radiation, and are therefore approaching the star at greater speed. This causes a radial separation of the particles (the linear structures in the cloud itself), with larger particles closer to the star and smaller ones further away. Eventually, most of the dust particles in the cloud will be vaporized by the heat of the star. (Note: The linear structures pointing away from the star itself (which is out-of-field at the top of the closeup images) in the HST image are not real; they are artifacts caused by the telescope's construction and overexposure of the star's light.)
 The apparent size of the reflection nebula is about 20 by 15 arcsec (from the images below). At the approximately 380 light year distance of Merope that corresponds to about 2200 AUs, or 0.036 light years.