Celestial Atlas
(IC 250 - 299) ←     IC Objects: IC 300 - 349 Link for sharing this page on Facebook     → (IC 350 - 399)
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Page last updated March 3, 2017
Corrected entry for IC 312, which is the actual NGC 1265
WORKING: historical / physical information

IC 300 (= PGC 2198416)
Discovered (Sep 15, 1888) by
Lewis Swift
A 15th-magnitude elliptical galaxy (type E0?) in Perseus (RA 03 14 16.0, Dec +42 24 55)
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 says that Swift's description of the starfield could have been better, and feels that a more suitable candidate may eventually surface.
Physical Information: Apparent size 0.55 by 0.55 arcmin?
SDSS image of elliptical galaxy IC 300
Above, a 2.4 arcmin wide closeup of IC 300
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near elliptical galaxy IC 300

IC 301 (= PGC 12074)
Discovered (Sep 15, 1888) by
Lewis Swift
A 13th-magnitude elliptical galaxy (type E0?) in Perseus (RA 03 14 48.0, Dec +42 13 21)
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 1.1 by 1.1 arcmin?
SDSS image of elliptical galaxy IC 301
Above, a 2.4 arcmin wide closeup of IC 301
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near elliptical galaxy IC 301

IC 302 (= PGC 11972)
Discovered (Dec 15, 1892) by
Stephane Javelle
A 13th-magnitude spiral galaxy (type SB(rs)bc) in Cetus (RA 03 12 51.4, Dec +04 42 23)
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 2.2 by 1.7 arcmin?
SDSS image of spiral galaxy IC 302
Above, a 2.4 arcmin wide closeup of IC 302
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 302

IC 303 (= PGC 962881)
Discovered (Feb 7, 1893) by
Stephane Javelle
A 15th-magnitude lenticular galaxy (type S0/a?) in Eridanus (RA 03 12 40.9, Dec -11 41 23)
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 0.65 by 0.45 arcmin?
DSS image of lenticular galaxy IC 303
Above, a 2.4 arcmin wide closeup of IC 303
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 306
DSS image of region near lenticular galaxy IC 303, also showing spiral galaxy IC 306

IC 304 (= PGC 12080)
Discovered (Sep 12, 1890) by
Sherburne Burnham
A 14th-magnitude spiral galaxy (type Sab pec?) in Perseus (RA 03 15 01.5, Dec +37 52 56)
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 1.0 by 0.55 arcmin?
DSS image of spiral galaxy IC 304 and elliptical galaxy IC 305
Above, a 2.4 arcmin wide closeup of IC 304 and 305
Below, a 12 arcmin wide region centered on the pair
DSS image of region near spiral galaxy IC 304 and elliptical galaxy IC 305

IC 305 (= PGC 12083)
Discovered (Sep 12, 1890) by
Sherburne Burnham
A 14th-magnitude elliptical galaxy (type E3 pec?) in Perseus (RA 03 15 03.7, Dec +37 51 38)
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 (which see for images)? Apparent size 0.95 by 0.7 arcmin?

IC 306 (= PGC 11985)
Discovered (Feb 7, 1893) by
Stephane Javelle
A 15th-magnitude spiral galaxy (type SABc pec?) in Eridanus (RA 03 13 00.2, Dec -11 42 57)
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 0.75 by 0.55 arcmin?
DSS image of spiral galaxy IC 306
Above, a 2.4 arcmin wide closeup of IC 306
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 303
DSS image of region near spiral galaxy IC 306, also showing lenticular galaxy IC 303

IC 307 (= PGC 12017)
Discovered (Dec 4, 1891) by
Stephane Javelle
A 13th-magnitude spiral galaxy (type (R)SB(r)a pec?) in Cetus (RA 03 13 45.4, Dec -00 14 30)
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 1.9 by 0.75 arcmin?
SDSS image of spiral galaxy IC 307
Above, a 2.4 arcmin wide closeup of IC 307
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 307

IC 308 (= PGC 12152)
Discovered (Sep 11, 1888) by
Lewis Swift
A 14th-magnitude lenticular galaxy (type SB0?) in Perseus (RA 03 16 16.1, Dec +41 10 53)
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 1.2 by 1.0 arcmin?
SDSS image of lenticular galaxy IC 308
Above, a 2.4 arcmin wide closeup of IC 308
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy IC 308

IC 309 (= PGC 12141)
Discovered (Sep 11, 1888) by
Lewis Swift
A 14th-magnitude lenticular galaxy (type SA0°(s)) in Perseus (RA 03 16 06.5, Dec +40 48 17)
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 1.05 by 1.05 arcmin?
SDSS image of lenticular galaxy IC 309
Above, a 2.4 arcmin wide closeup of IC 309
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy IC 309

IC 310 (= PGC 12171)
Discovered (Nov 3, 1888) by
Edward Swift
A 13th-magnitude lenticular galaxy (type SA0°(r)?) in Perseus (RA 03 16 43.2, Dec +41 19 29)
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". Noted in Swift's paper as discovered by Edward.
Physical Information: Apparent size 1.4 by 1.4 arcmin?
SDSS image of lenticular galaxy IC 310
Above, a 2.4 arcmin wide closeup of IC 310
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy IC 310

IC 311 (= PGC 12177)
Discovered (Oct 10, 1888) by
Lewis Swift
A 14th-magnitude spiral galaxy (type Sb pec?) in Perseus (RA 03 16 47.0, Dec +40 00 15)
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 1.7 by 1.2 arcmin?
SDSS image of spiral galaxy IC 311
Above, a 2.4 arcmin wide closeup of IC 311
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 311

IC 312 (= PGC 12279 =
NGC 1265)
Discovered (Nov 14, 1884) by Guillaume Bigourdan (and now listed as NGC 1265)
Independently discovered (Nov 3, 1888) by Lewis Swift (and later listed as IC 312)
A magnitude 13.4 lenticular galaxy (type E/S0?) in Perseus (RA 03 18 08.6, Dec +41 45 18)
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.

WORKING HERE: Adding Dreyer IC entries

IC 313 (= PGC 12558)
Discovered (Sep 14, 1888) by
Lewis Swift (VIII-33)
A 14th-magnitude elliptical galaxy (type E1?) in Perseus (RA 03 20 58.3, Dec +41 53 37)
Apparent size 1.05 by 0.9 arcmin.
SDSS image of elliptical galaxy IC 313
Above, a 2.4 arcmin wide closeup of IC 313
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 316
SDSS image of elliptical galaxy IC 313, also showing the pair of spiral galaxies listed as IC 316

IC 314 (=
NGC 1289 = PGC 12342)
Discovered (Sep 1, 1886) by Lewis Swift (and later listed as NGC 1289)
Discovered (Dec 14, 1887) by Guillaume Bigourdan (and later listed as IC 314)
A 13th-magnitude lenticular galaxy (type S0?) in Eridanus (RA 03 18 49.8, Dec -01 58 23)
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.

IC 315 (= PGC 12364)
Discovered (Jan 11, 1894) by
Stephane Javelle (584)
A 14th-magnitude spiral galaxy (type Sab?) in Cetus (RA 03 19 09.3, Dec +04 02 19)
Apparent size 0.9 by 0.45 arcmin.
SDSS image of spiral galaxy IC 315
Above, a 2.4 arcmin wide closeup of IC 315
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 315

IC 316 (= PGC 12576 + PGC 12578)
Discovered (Sep 14, 1888) by
Lewis Swift (VIII-34)
A pair of 14th-magnitude interacting galaxies in Perseus
PGC 12576 = A spiral galaxy (type SBb pec?) at RA 03 21 19.9, Dec +41 55 43
PGC 12578 = A spiral galaxy (type S pec?) at RA 03 21 19.9, Dec +41 55 55
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 0.4 by 0.1 arcmin, while the similar region for PGC 12578 is 0.25 by 0.2 arcmin. The extended cloud of material surrounding both galaxies covers a region 1.25 by 1.1 arcmin in size.
SDSS image of interacting galaxies PGC 12576 and 12578, which comprise IC 316
Above, a 2.4 arcmin wide closeup of IC 316
Below, a 12 arcmin wide region centered on the pair, also showing IC 313
SDSS image of region near the interacting galaxies that comprise IC 316; also shown is elliptical galaxy IC 313

IC 317 (= PGC 12346)
Discovered (Jan 2, 1892) by
Stephane Javelle (109)
A 14th-magnitude spiral galaxy (type SB?) in Eridanus (RA 03 18 55.4, Dec -12 44 23)
Apparent size 0.75 by 0.55 arcmin.
DSS image of spiral galaxy IC 317
Above, a 2.4 arcmin wide closeup of IC 317
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 317

IC 318 (= PGC 12532)
Discovered (Dec 1, 1891) by
Stephane Javelle (110)
A 14th-magnitude spiral galaxy (type Sbc?) in Eridanus (RA 03 20 43.8, Dec -14 34 05)
Apparent size 0.9 by 0.4 arcmin.
DSS image of spiral galaxy IC 318
Above, a 2.4 arcmin wide closeup of IC 318
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 318

IC 319
Recorded (Dec 27, 1886) by
Guillaume Bigourdan
A 15th-magnitude star in Perseus (RA 03 23 29.0, Dec +41 24 59)
Per Dreyer, IC 319 (Bigourdan #141, 1860 RA 03 14 13, NPD 49 06) is "stellar, = 13th magnitude". 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.
SDSS image of region near the star listed as IC 319, also showing lenticular galaxy PGC 2180624, which is sometimes misidentified as IC 319
Above, a 12 arcmin wide region centered on IC 319, also showing PGC 2180624

PGC 2180624 (not =
IC 319)
Not an IC object but listed here since sometimes misidentified as IC 319
A 16th-magnitude lenticular galaxy (type SB0?) in Perseus (RA 03 23 27.0, Dec +41 24 23)
Based on a recessional velocity of 4625 km/sec, PGC 2180624 is about 215 million light years away. Given that and its apparent size of 0.65 by 0.65 arcmin, it is about 40 thosuand light years across.
SDSS image of lenticular galaxy PGC 2180624, which is sometimes misidentified as IC 319, also showing the star listed as IC 319
Above, a 2.4 arcmin wide closeup of PGC 2180624 and IC 319 (which see for a wider view)

IC 320 (= PGC 12819)
Discovered (Sep 14, 1888) by
Lewis Swift (VIII-35)
A 14th-magnitude spiral galaxy (type SB(rs)ab) in Perseus (RA 03 25 59.2, Dec +40 47 21)
Apparent size 1.4 by 1.25 arcmin.
SDSS image of spiral galaxy IC 320
Above, a 2.4 arcmin wide closeup of IC 320
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 320

IC 321 (= PGC 12742)
Discovered (Dec 7, 1891) by
Stephane Javelle (111)
A 15th-magnitude lenticular galaxy (type S0/a?) in Eridanus (RA 03 24 29.5, Dec -14 59 09)
Apparent size 0.85 by 0.85 arcmin.
DSS image of lenticular galaxy IC 321
Above, a 2.4 arcmin wide closeup of IC 321
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near lenticular galaxy IC 321

IC 322 (= PGC 12820)
Discovered (Dec 15, 1892) by
Stephane Javelle (585)
A 15th-magnitude spiral galaxy (type Scd?) in Taurus (RA 03 26 00.5, Dec +03 40 49)
Apparent size 0.75 by 0.75 arcmin.
SDSS image of spiral galaxy IC 322
Above, a 2.4 arcmin wide closeup of IC 322
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 322

IC 323
Recorded (Oct 27, 1888) by
Lewis Swift
A 13th-magnitude grouping of stars in Perseus (RA 03 29 33.5, Dec +41 51 21)
Per Dreyer, IC 323 (Swift list VIII (#36), 1860 RA 03 20 11, NPD 48 37.6) is "extremely faint, pretty small, round, preceding 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.
SDSS image of region near the group of stars listed as IC 323, also showing spiral galaxy NGC 1334
Above, a 12 arcmin wide region centered on the probable IC 323, also showing NGC 1334

IC 324 (=
NGC 1331 = PGC 12846)
Discovered (Dec 19, 1799) by William Herschel (and later listed as NGC 1331)
Discovered (Dec 3, 1888) by Guillaume Bigourdan (and later listed as IC 324)
A 13th-magnitude elliptical galaxy (type E2?) in Eridanus (RA 03 26 28.2, Dec -21 21 20)
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.

IC 325 (= PGC 1025189)
Discovered (Jan 28, 1892) by
Stephane Javelle (112)
A 16th-magnitude spiral galaxy (type S(rs)bc?) in Eridanus (RA 03 30 48.8, Dec -07 02 47)
Apparent size 0.75 by 0.75 arcmin.
SDSS image of spiral galaxy IC 325
Above, a 2.4 arcmin wide closeup of IC 325
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 325

IC 326 (= PGC 13030)
Discovered (Dec 1, 1891) by
Stephane Javelle (113)
A 14th-magnitude lenticular galaxy (type SA0-?) in Eridanus (RA 03 30 36.6, Dec -14 25 31)
Apparent size 1.3 by 0.95 arcmin.
SDSS image of lenticular galaxy IC 326 superimposed on a DSS background to fill in missing areas
Above, a 2.4 arcmin wide closeup of IC 326
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy IC 326 superimposed on a DSS background to fill in missing areas

IC 327 (= PGC 13057)
Discovered (Dec 12, 1892) by
Stephane Javelle (586)
A 15th-magnitude spiral galaxy (type Sbc pec?) in Eridanus (RA 03 31 10.0, Dec -14 41 32)
Apparent size 0.75 by 0.45 arcmin.
DSS image of spiral galaxy IC 327
Above, a 2.4 arcmin wide closeup of IC 327
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 328
DSS image of region near spiral galaxy IC 327, also showing spiral galaxy IC 328

IC 328 (= PGC 13063)
Discovered (Dec 10, 1892) by
Stephane Javelle (114)
A 14th-magnitude spiral galaxy (type Sc pec?) in Eridanus (RA 03 31 11.0, Dec -14 38 16)
Apparent size 0.65 by 0.5 arcmin.
DSS image of spiral galaxy IC 328
Above, a 2.4 arcmin wide closeup of IC 328
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 327
DSS image of region near spiral galaxy IC 328, also showing spiral galaxy IC 327; partially replaced by SDSS photomosaic where available

IC 329 (= PGC 13109)
Discovered (Dec 4, 1891) by
Stephane Javelle (115)
A 14th-magnitude spiral galaxy (type Sa?) in Taurus (RA 03 32 01.4, Dec +00 16 46)
Apparent size 1.05 by 0.55 arcmin.
SDSS image of spiral galaxy IC 329
Above, a 2.4 arcmin wide closeup of IC 329
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 330 and 331
SDSS image of region near spiral galaxy IC 329, also showing spiral galaxy IC 330 and lenticular galaxy IC 331

IC 330 (= PGC 13117)
Discovered (Dec 4, 1891) by
Stephane Javelle (116)
A 14th-magnitude spiral galaxy (type SBab?) in Taurus (RA 03 32 08.0, Dec +00 21 12)
Apparent size 1.25 by 0.35 arcmin.
SDSS image of spiral galaxy IC 330
Above, a 2.4 arcmin wide closeup of IC 330
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 329 and 331
SDSS image of region near spiral galaxy IC 330, also showing spiral galaxy IC 329 and lenticular galaxy IC 331

IC 331 (= PGC 13119)
Discovered (Dec 4, 1891) by
Stephane Javelle (117)
A 14th-magnitude lenticular galaxy (type S0/a?) in Taurus (RA 03 32 19.1, Dec +00 16 58)
Apparent size 1.3 by 0.8 arcmin.
SDSS image of lenticular galaxy IC 331
Above, a 2.4 arcmin wide closeup of IC 331
Below, a 12 arcmin wide region centered on the galaxy, also showing IC 329 and 330
SDSS image of region near lenticular galaxy IC 331, also showing spiral galaxies IC 329 and 330

IC 332 (= PGC 13137)
Discovered (Dec 29, 1893) by
Stephane Javelle (587)
A 14th-magnitude spiral galaxy (type (R)SAB0/a?(rs)) in Taurus (RA 03 32 37.4, Dec +01 22 58)
Apparent size 0.95 by 0.5 arcmin.
DSS image of spiral galaxy IC 332
Above, a 2.4 arcmin wide closeup of IC 332
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 332

IC 333
Recorded (Nov 21, 1889) by
Guillaume Bigourdan (143)
A nonexistent object in Eridanus (RA 03 34 02.3, Dec -05 06 37)
Per Dreyer, IC 333 (Bigourdan #143, 1860 RA 03 27 06, NPD 95 35) is "extremely faint, 8.8 magnitude star 4' to northeast". The position precesses to RA 03 34 02.3, Dec -05 06 37 (whence the position above), but although there is a 9th-magnitude star 4 arcmin to the northeast (confirming the correct field of view), there is nothing nearby save for a 17th-magnitude star. Per Corwin, Bigourdan only observed the object once and even then only 'suspected' its existence, so it is almost certainly a nonexistent object.
DSS image of region near the position of apparently nonexistent IC 333, also showing spiral galaxy NGC 1358
Above, a 12 arcmin wide region centered on the position measured for IC 333, also showing NGC 1358

IC 334 (= PGC 13759)
Discovered (Sep 30, 1891) by
William Denning
An 11th-magnitude spiral galaxy (type Sa pec?) in Camelopardalis (RA 03 45 17.1, Dec +76 38 15)
Apparent size 3.4 by 2.6 arcmin. (Perhaps a starburst galaxy?)
DSS image of spiral galaxy IC 334
Above, a 4 arcmin wide closeup of IC 334
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 334

IC 335 (=
IC 1963 = PGC 13277)
Discovered (Oct 15, 1887) by Lewis Swift (and later listed as IC 335)
Rediscovered (1897) by Lewis Swift (and later listed as IC 1963)
A 12th-magnitude lenticular galaxy (type S0?) in Fornax (RA 03 35 31.1, Dec -34 26 49)
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 and 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: Apparent size 1.9 by 0.3 arcmin (size and position based on HST image). Approximate distance 60 million light years, based on membership in the Fornax Galaxy Cluster. Given that and its apparent size, probably about 45 thousand light years across.
DSS image of region near lenticular galaxy IC 335
Above, a 12 arcmin wide DSS image centered on IC 335
Below, a 2 arcmin wide image of the galaxy (Image Credit ESA/Hubble/NASA)
HST image of lenticular galaxy IC 335

IC2 comment for IC 336,
341, 353, 354 and 360
The second IC adds "336, etc. Compare M.N., lvii. p. 12, picture of exterior nebulosities around the Pleiades, and M. Wolf: "Die Aussen-Nebel der Plejaden," Abh. d. K. Bayr. Akad., 1900, 4°." (336, etc means the nebulosities listed as IC 336, 341, 353, 354 and 360.) The reference to M.N. p. 12 is to Barnard's sketch of nebulosity near the Pleiades published in 1896, and shown as a labeled image at each of the five IC entries. The 1900 Abhandlungen der Königlich-Bayerischen Akademie der Wissenschaften paper states that Wolf also created a sketch of the nebulosities near the Pleiades in 1894, and privately transmitted it at that time to individual astronomers. Whether he failed to send it to Dreyer, or Dreyer felt it to be less satisfactory than Barnard's sketch (which despite being published in 1896 was probably privately transmitted to Dreyer at the time of Barnard's first publication, in 1894) is unclear. In any event, Dreyer used Barnard's sketch to identify the nebulae in the region and estimate their positions, and credited him with the discoveries listed in the IC. Per the 1900 paper, Wolf felt that his 1894 sketch was too crude to be satisfactory, and spent many years attempting to obtain better images of the region, culminating with his 1900 publication (not because he felt that he had completely succeeded in creating a proper representation of the nebulae in the region, but because he heard that Barnard had published sketches of the region, and felt that under the circumstances he should publish his own efforts, even if they weren't what he had hoped they might become). Since Dreyer did not suggest any corrections to his IC listings as a result of the 1900 paper, but merely referred the interested reader to Wolf's exhaustively detailed discussion and images, it seems very unlikely that any changes are needed in the entries for the five objects, so I will leave them as-is for now. However, it seemed more appropriate to mention the IC2 note and discuss its significance than to ignore it, hence this brief entry. Note: To read Wolf's paper, click here.

IC 336
Discovered (Dec 6, 1893) by
Edward Barnard
An emission nebula in Taurus (near RA 03 37, Dec +23.6)
Per Dreyer, IC 336 (Barnard [A.N.](#3253), 1860 RA 3 30±, NPD 67) is "very faint, most extremely large, very diffuse" (#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.)
MNRAS 57,12,1897 sketch of nebulosity near the Pleiades labeled to show the location of emission nebulae IC 336, 341, 353, 354 and 360
Above, Barnard's sketch of the region near the Pleiades
(The smudge to the left of the label is what Dreyer used for IC 336)
Below, a 2 degree wide region centered on the position of IC 336, using normal image adjustments
DSS image of region centered on emission nebula IC 336
Below, the above image using extreme digital photo-enhancement (Processing by Courtney Seligman)
Enhanced DSS image of region centered on emission nebula IC 336

IC 337
Recorded (Dec 25, 1889) by
Lewis Swift
A lost or nonexistent object in Eridanus (RA 03 37 03.9, Dec -06 43 19)
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, but Corwin says it almost certainly has too low a surface brightness for Swift to have seen it. He adds that 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 appears 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 deserve the IC entry after all.
SDSS image of region near the probably nonexistent IC 337, also showing spiral galaxy PGC 13308 and lenticular galaxy PGC 145722, possible but unlikely candidates for the IC entry
Above, a 28 arcmin wide region centered on the position of IC 337, also showing PGC 13308 and 145722

PGC 13308 (a possible but unlikely candidate for
IC 337)
Probably not an IC object but listed here because because mentioned in the discussion of IC 337
A 15th-magnitude spiral galaxy (type SB(s)m) in Eridanus (RA 03 36 21.3, Dec -06 42 54)
(See IC 337 for a discussion of this object's relevance to that entry.) Based on a recessional velocity of 3085 km/sec, PGC 13308 is about 145 million light years away. Given that and its apparent size of 1.6 by 0.95 arcmin, it is about 65 thousand light years across.
SDSS image of spiral galaxy PGC 13308, sometimes identified (though probably incorrectly) as IC 337
Above, a 2.4 arcmin wide closeup of PGC 13308
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy PGC 13308, sometimes identified (though probably incorrectly) as IC 337

PGC 145722 (a possible but very unlikely candidate for
IC 337)
Almost certainly not an IC object but listed here because mentioned in the discussion of IC 337
A 14th-magnitude lenticular galaxy (type S0?) in Eridanus (RA 03 37 33.4, Dec -06 31 14)
(See IC 337 for a discussion of this object's relevance to that entry.) Apparent size 1.05 by 0.55 arcmin.
SDSS image of lenticular galaxy PGC 145722, sometimes mentioned in connection with IC 337
Above, a 2.4 arcmin wide closeup of PGC 145722
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy PGC 145722, sometimes mentioned in connection with IC 337

IC 338 (= PGC 13373)
Discovered (Oct 13, 1891) by
Stephane Javelle (118)
A 14th-magnitude spiral galaxy (type Sc?) in Taurus (RA 03 37 38.1, Dec +03 07 06)
Apparent size 0.85 by 0.6 arcmin.
DSS image of spiral galaxy IC 338
Above, a 2.4 arcmin wide closeup of IC 338
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 338

IC 339
Recorded (Sep 22, 1887) by
Ormond Stone
A 12th-magnitude star in Eridanus (RA 03 38 01.9, Dec -18 23 58)
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 to the northeast of the star listed above, and there is nothing else nearby, so given the IC description the identification with the star seems certain.
DSS image of region near the star listed as IC 339, also showing lenticular galaxy NGC 1383
Above, a 12 arcmin wide region centered on IC 339, also showing NGC 1383

IC 340 (= PGC 13464)
Discovered (Jan 11, 1894) by
Stephane Javelle (588)
A 14th-magnitude spiral galaxy (type SABcd?) in Eridanus (RA 03 39 29.1, Dec -13 06 55)
Apparent size 1.5 by 0.55 arcmin.
SDSS image of spiral galaxy IC 340
Above, a 2.4 arcmin wide closeup of IC 340
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near spiral galaxy IC 340 overlaid on a DSS background to show areas otherwise not covered

IC 341
Discovered (Dec 6, 1893) by
Edward Barnard
A reflection and emission nebula in Taurus (near RA 03 41, Dec +22.1)
Per Dreyer, IC 341 (Barnard [A.N.](#3253), 1860 RA 03 33±, NPD 68 30±) is "very faint, most extremely large, very diffuse" (#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.
MNRAS 57,12,1897 sketch of nebulosity near the Pleiades labeled to show the location of emission nebulae IC 336, 341, 353, 354 and 360
Above, Barnard's sketch of the region near the Pleiades
(The smudge below the label is what Dreyer used for IC 341)
Below, a 1.5 degree wide region centered on the position of IC 341, using normal image adjustments
DSS image of region centered on emission nebula IC 341
Below, a 1.2 degree wide closeup, with extreme digital enhancement (Processing by Courtney Seligman)
Enhanced DSS image of region centered on emission nebula IC 341
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. As long as such editing is done carefully and without any effort to falsify the reality behind the image, it is considered ethical and desirable; but if I hadn't mentioned the juggling involved, would you have suspected that anything might be amiss?

IC 342 (= PGC 13826)
Discovered (Aug 19, 1892) by
William Denning
An 8th-magnitude spiral galaxy (type SAB(rs)cd) in Camelopardalis (RA 03 46 48.6, Dec +68 05 44)
Per Dreyer, IC 342 (1860 RA 03 33 20, NPD 22 21) is "pretty bright, very small, 12th magnitude star close to the 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. 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 22 by 21 arcmin, the galaxy is about 60 thousand light years across.
NOAO image of spiral galaxy IC 342
Above, a "deep" view of IC 342, with hydrogen emission nebulae highlighted by red filters
(Image Credit: T.A. Rector/University of Alaska Anchorage, H. Schweiker/WIYN and AURA/NSF/NOAO)
Below, a closeup of the central region (Image Credit: Ken and Emilie Siarkiewicz/Adam Block/AURA/NSF/NOAO)
NOAO closeup of spiral galaxy IC 342
Below, a more nearly natural-color 24 arcmin wide view centered on the galaxy
DSS image of region near spiral galaxy IC 342

IC 343 (= PGC 13495)
Discovered (Oct 14, 1887) by
Frank Muller (163)
A 13th-magnitude lenticular galaxy (type SB0+(rs)?) in Eridanus (RA 03 40 07.1, Dec -18 26 37)
Based on a recessional velocity of 1840 km/sec, 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 1.85 by 0.8 arcmin, it is about 45 thousand light years across.
DSS image of lenticular galaxy IC 343
Above, a 2.4 arcmin wide closeup of IC 343
Below, a 12 arcmin wide region centered on the galaxy, also showing part of NGC 1407
DSS image of region near lenticular galaxy IC 343, also showing the northern outline of elliptical galaxy NGC 1407

IC 344 (= PGC 13568)
Discovered (Oct 17, 1827) by
John Herschel (GC 756 = JH 305)
A 14th-magnitude spiral galaxy (type SBbc?) in Eridanus (RA 03 41 29.5, Dec -04 39 57)
Apparent size 0.85 by 0.35 arcmin.
DSS image of spiral galaxy IC 344
Above, a 2.4 arcmin wide closeup of IC 344
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 344

IC 345 (= PGC 13552)
Discovered (Oct 22, 1887) by
Ormond Stone (168)
A 14th-magnitude lenticular galaxy (type S0/a?) in Eridanus (RA 03 41 09.0, Dec -18 18 51)
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. Apparent size 0.85 by 0.75 arcmin.
DSS image of lenticular galaxy IC 345
Above, a 2.4 arcmin wide closeup of IC 345
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near lenticular galaxy IC 345

IC 346 (= PGC 13575)
Discovered (Oct 22, 1887) by
Frank Muller
A 13th-magnitude spiral galaxy (type SB0+(rs)) in Eridanus (RA 03 41 44.7, Dec -18 16 02)
Per Dreyer, IC 346 (Ormond Stone (#151), 1860 RA 03 35 06, NPD 108 49.4) is "very faint, very small". 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. Based on a recessional velocity of 2085 km/sec, PGC 13575 is about 95 million light years away. Given that and its apparent size of 2.0 by 1.5 arcmin, it is about 55 thousand light years across.
DSS image of spiral galaxy IC 346
Above, a 2.4 arcmin wide closeup of IC 346
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 346

Leander McCormick #151 (not =
IC 346)
Not an IC object but listed here for historical reasons
Recorded (Sep 22, 1889) by Ormond Stone
A 15th-magnitude star in Eridanus (RA 03 41 23.2, Dec -18 22 08)
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".
DSS image of region near the star that is probably the original (but incorrect) IC 346, also showing lenticular galaxy IC 345 and part of spiral galaxy IC 346
Above, a 12 arcmin wide region centered on LMcC#151, also showing IC 345 and part of IC 346

IC 347 (= PGC 13622)
Discovered (Dec 25, 1889) by
Lewis Swift (IX-14)
A 13th-magnitude spiral galaxy (type SAB0°?(r)) in Eridanus (RA 03 42 32.6, Dec -04 17 56)
Apparent size 1.25 by 0.95 arcmin.
DSS image of spiral galaxy IC 347
Above, a 2.4 arcmin wide closeup of IC 347
Below, a 12 arcmin wide region centered on the galaxy
DSS image of region near spiral galaxy IC 347

IC 348 (=
IC 1985 = OCL 409)
Discovered (Dec 1, 1866) by Truman Safford (70) (and later listed as IC 348)
Discovered (1890's) by Edward Barnard (and later listed as IC 1985)
A 7th-magnitude star cluster (type IV2pn) & reflection nebula in Perseus (RA 03 44 34.2, Dec +32 09 46)
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. 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, they span about 15 light years, though the bright central region is only a fifth that size.
DSS image of open cluster and emission and reflection nebula IC 348
Above, a 12 arcmin (= 2.5 light year) wide closeup of IC 348
Below, a half degree wide infrared view (Image Credits: NASA/JPL-Caltech/L. Cieza (U. of Texas Austin))
Spitzer Space Telescope infrared image of open cluster and emission nebula IC 348
Below, a half-degree wide region centered on IC 348; the 3rd-magnitude star is ο Persei
DSS image of region near open cluster and emission and reflection nebula IC 348

IC 349, Barnard's Merope Nebula (part of the Merope Nebula)
Discovered (Nov 14, 1890) by
Edward Barnard
A reflection nebula in Taurus (RA 03 46 20.1, Dec +23 56 23)
The Pleiades is an open cluster surrounded by a reflection nebula caused by dust which happens to be in the region the cluster is passing through, and has nothing to do with the dust and gas out of which it 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 a wide-field image of the Merope nebula, Barnard's nebula is completely lost in the glare of the star. However, the HST image immediately below shows the knot in detail, and 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. Smaller dust particles are affected more than larger ones, so linear streams are formed, with the more massive particles near the apex (closer to the star). Eventually, most of the particles in this knot will be vaporized by the heat of the star. The apparent size of the reflection nebula is about 0.35 by 0.25 arcmin. At the 380 light year distance of the Pleiades this corresponds to about 2400 AUs, or 0.4 light years.
HST image of reflection nebula IC 349
Above, a closeup of IC 349; the image spans 3400 AUs, and Merope is just outside the field of view
(Hubble Heritage Team, George H. Herbig & Theodore Simon (IfA, U. Hawaii), NASA)
Below, a half degree wide region centered on Merope, showing the entire Merope nebula
DSS image of region near reflection nebula IC 349
Celestial Atlas
(IC 250 - 299) ←     IC Objects: IC 300 - 349     → (IC 350 - 399)