In researching the names of galaxies involved in the Arps among various galaxy catalogs, the author and friends noted a number of irregularities or inconsistencies. Perhaps this is a product of having too many galaxy catalogs. These discrepancies may be bothersome to some observers and are provided for their use. Perhaps a very energetic person can resolve the discrepancies or convince the catalog builders to converge on a single interpretation. Perhaps it is better to enjoy the mystery.
Arp 7 PGC lists MCG+3-23-009 (IC2411) rather than MCG-3-23-009
which appears to be the same galaxy in the original Arp image.
Arp 30 Suffix discrepancy: NGC 6365A, B
Arp 32 UGC10770B NED is UGC10770 RC3. Also, there is no A in RC3
Arp 51 NED identifies as MCG-02-01-024/NGC 7828 but PGC suggests
the galaxy in Arp's image is a galaxy at a different location
called PGC 475.
Arp 54 Should this include PGC 9103?
Arp 57 Positional discrepancies for MCG+03-34-013 and MCG+03-34-012
between NED and PGC.
Arp 59 Suffix discrepancy: NGC 341A, B
Arp 63 NED proposes MCG+06-21-067 as the companion to NGC 2944
while PGC suggests another galaxy PGC27534 which NED
does not recognize. Also suffix discrepancy: NGC 2944A, B
Arp 68 original paper identifies NGC 7756, NED references NGC 7757.
Arp 87 Suffix discrepancy: NGC 3808A,
Arp 89 Irregularities in MCG: -12-22-006 and +02-22-006 (RC3) are
both proposed for the fainter companion to 2648.
Arp 97 CfA Redshift files identify UGC 07085 in a different part
of the sky
Arp 102 PGC and RC3 interpret MCG+08-31-042 and -041 differently.
PCG position for -042 is inconsistent with Arp's picture
and Hubble Guide Star Catalog. RC3 location for -041 is
consistent with NED's interpretation of -042 as the
southern E0 galaxy.
Arp 105 Suffix discrepancy: NGC 3561A, B
Arp 106 Suffix discrepancy: NGC 4211A
Arp 111 NED references to MCG+06-31-046 galaxies do not appear in
Arp's image for Arp 111.
Arp 113 NED identifies only NGC 70, but Arp's categorization
identifies it as "E or E-like galaxy close to and perturbing
a spiral". This categorization would imply that NGC 71 (E) or
NGC 68 (S0) would be the primary galaxy and NGC 70 is the
perturbed spiral. While current redshifts have NGC 71 closer
to NGC 70 and NGC 71 is visually closer, both are included.
Arp 114 original paper identifies NGC 2276, NED references NGC 2300.
Arp 118 Historical confusion between NGC 1141 and 1143.
Historical confusion between NGC 1142 and 1144.
Arp 122 original paper identifies NGC 6039, NED references NGC 6040A&B.
RC3 suggests that 6039 is a single star
Arp 144 NGC7828 NED A is B in RC3 and NGC7829 NED is B and A in RC3
Arp 145 PGC implies that the objects are UGC 1840 and PGC 9060
Arp 146 Ring A NED is Ring B and VV790 coordinates differ in PGC
Arp 147 Suffix discrepancy IC298/298A
Arp 150 Suffix discrepancy: NGC 7609A
Arp 170 Suffix discrepancy: NGC 7578A, B
Arp 174 NGC 3068 has a companion (3068 A&B)
Arp 176 NED A & B is RC3 B & A
Arp 181 Original paper identifies NGC 3210 and 12, NED references 3212
and 15.
Arp 218 Can't find name of southwest component
Arp 220 Original paper and NED (2 obj) lists IC 4553, DSFG implies
IC4553&4554
Arp 256 RC3 implies that NGC71 and NGC 68 should be included
Arp 259 Suffix discrepancy: NGC 1741A, B, C, D (IC 399 may be included)
Arp 272 Arp's paper lists NGC 6054. Current interpretation of Abell
2151 labels the galaxies in Arp's image as NGC6050 and IC1179.
Arp 274 Suffix discrepancy: NGC 5679A, B, C, NGC5679B NED is A in RC3
Arp 278 Suffix discrepancy: NGC 7253A, B
Arp 282 NED includes NGC 169A, DSFG implies it should be IC 1559.
Arp 288 original paper identifies NGC 5221, 22 & 26, NED omits 3226.
RC3 implies that 5222 is a double galaxy and 5226 is out of
the field.
Arp 295 Original paper identifies IC 1505, NED and RC3 references
MCG-01-60-21,
Arp 296 Confusion with Arp 299: Original paper identifies NGC 3690
and IC 694,
Arp 299 Confusion with Arp 296: Original paper references No names,
Arp 310 NED and original paper list IC 1259. RC3 implies it should be 1258
No IC1259 objects in RC3
Arp 311 (same as for Arp 310) plus confusion between IC 1260 with KAZ 140
Arp 312 NED identifies Arp 312 as MCG+08-31-004. The PGC
interpretation suggests that this galaxy (not apparent on
POSS) is too large and slightly south of the location
implied by field stars in Arp's image. MCG+08-31-006 is
better placed but not in the correct place. The Hubble
GSC misidentifies the involved galaxies as stars.
Arp 314 MCG-03 objects in NED are MCG-01 in RC3 and agree w/picture
Arp 316 Original paper identifies NGC 3190, NED references 3187, 89
and 93. NGC2000 also implies that 3190 should be a part
of the group. 3189 is not in RC2 but is listed in NGC2000.
DSFG implies a group of 3187, 90 and 93.
Arp 319 Suffix discrepancy: NGC 7318A, B
Arp 321 Numbering inconsistencies between NED and RC3:
-10 to -12; -9 to -8; -8 to -9; -11 to -12
Arp 323 Suffix discrepancy: NGC 7783B, RC3 suggests MCG+0-60-58/+0-60-59
Arp 325 NED identifies this as ESO 601- G 018. ESO on NASA CD-ROM
does not recognize such a galaxy but has ESO 532- G 18
near the same location. MegaStar identifies ESO 601-18B
(MCG-04-52-14)
Arp 331 Original paper identifies NGC 375-88, NED lists NGC 379, 380,
382-386, and 388. Also, sources disagree on labeling and location
of galaxies NGC387 and 388.
Page updated April 5, 1999 by Dennis Webb.
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