Celestial Atlas
(NGC 3350 - 3399) ←NGC Objects: NGC 3400 - 3449 Link for sharing this page on Facebook→ (NGC 3450 - 3499)
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3400, 3401, 3402, 3403, 3404, 3405, 3406, 3407, 3408, 3409, 3410, 3411, 3412, 3413, 3414, 3415, 3416,
3417, 3418, 3419, 3420, 3421, 3422, 3423, 3424, 3425, 3426, 3427, 3428, 3429, 3430, 3431, 3432, 3433,
3434, 3435, 3436, 3437, 3438, 3439, 3440, 3441, 3442, 3443, 3444, 3445, 3446, 3447, 3448, 3449

Page last updated May 22, 2021
Completed NGC 3445 and its "companions"
Updated Steinicke phyical data, Corwin positions

Finished posting all original NGC entries

NGC 3400 (= PGC 32499)
Discovered (Apr 11, 1785) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.2 spiral galaxy (type SBa?) in Leo Minor (RA 10 50 45.5, Dec +28 28 09)
Historical Identification: Per Dreyer, NGC 3400 (= GC 2220 = JH 768 = WH II 361, 1860 RA 10 43 03, NPD 60 47.4) is "pretty faint, small, round, brighter middle".
Physical Information:
SDSS image of region near spiral galaxy NGC 3400
Above, a 12 arcmin wide SDSS image centered on NGC 3400
Below, a 2.4 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 3400

NGC 3401
Recorded (Apr 13, 1784) by
William Herschel
A lost or nonexistent object in Sextans (RA ??, Dec ??)
Historical Identification: Per Dreyer, NGC 3401 (= WH III 88, 1860 RA 10 43 04±, NPD 83 28) is "extremely faint (not verified)".
Corwin lists a possible trio of stars at RA 10 50 03.8, Dec +05 47 06
Physical Information:

NGC 3402 (=
NGC 3411 = PGC 32479)
Discovered (Mar 25, 1786) by William Herschel (and later listed as NGC 3411)
Discovered (1880) by Andrew Common (and later listed as NGC 3402)
A magnitude 11.9 elliptical galaxy (type E0?) in Hydra (RA 10 50 26.1, Dec -12 50 42)
Historical Identification: Per Dreyer, NGC 3402 (Common (#6), 1860 RA 10 43 11, NPD 101 56) is "faint, round".
Physical Information:

Corwin lists a possible companion () at RA 10 50 23.0, Dec -12 51 06

NGC 3403 (= PGC 32719)
Discovered (Apr 3, 1785) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 12.2 spiral galaxy (type Sbc?) in Draco (RA 10 53 54.9, Dec +73 41 26)
Historical Identification: Per Dreyer, NGC 3403 (= GC 2221 = JH 767 = WH II 335, 1860 RA 10 43 15, NPD 15 34.6) is "pretty faint, large, irregularly extended, very gradually brighter middle".
Physical Information:

NGC 3404 (=
IC 2609 = PGC 32466)
Discovered (1880) by Andrew Common (and later listed as NGC 3404)
Also observed (date?) by Herbert Howe (while listed as NGC 3404)
Discovered (Apr 19, 1898) by Guillaume Bigourdan (and later listed as IC 2609)
A magnitude 13.2 spiral galaxy (type SBab?) in Hydra (RA 10 50 18.0, Dec -12 06 31)
Historical Identification: Per Dreyer, NGC 3404 (Common (#7), 1860 RA 10 43 17, NPD 101 08) is "pretty bright, very large, extended east-west".
The second IC lists a corrected NPD (per Howe) of 101 22.0.
Physical Information:

NGC 3405 (= PGC 32414)
Discovered (Apr 1, 1864) by
Albert Marth
A magnitude 13.3 lenticular galaxy (type E/S0?) in Leo (RA 10 49 43.3, Dec +16 14 20)
Historical Identification: Per Dreyer, NGC 3405 (= GC 5537, Marth 206, 1860 RA 10 43 18, NPD 73 01) is "faint, extremely small, almost stellar, close to small (faint) star".
Physical Information:

PGC 32418 (not part of
NGC 3405)
Not an NGC object but listed here because sometimes misidentified as part of NGC 3405
A magnitude 14.4 lnticular galaxy (type S0?) in Leo (RA 10 49 44.4, Dec +16 14 32)
Some references mistakenly list this galaxy as part of NGC 3405. In addition, they typically use the wrong PGC designations for the two galaxies, and sometimes assign the right ascension and/or declination for one to the other. However, there is no doubt that PGC 32418 is the fainter, northeastern "member" of the apparent pair.

NGC 3406 (= PGC 32580 + PGC 93106)
Discovered (Feb 17, 1831) by
John Herschel
A pair of galaxies in Ursa Major (RA 10 51 44.1, Dec +51 01 25)
PGC 32580 = A magnitude 12.7 lenticular galaxy (type E/S0?) at RA 10 51 43.6, Dec +51 01 20
PGC 93106 = A magnitude 12.9 peculiar galaxy (type pec?) at RA 10 51 44.5, Dec +51 01 30
Historical Identification: Per Dreyer, NGC 3406 (= GC 2222 = JH 771, 1860 RA 10 43 18, NPD 38 13.9) is "pretty bright, round, pretty gradually brighter middle".
Physical Information:

NGC 3407 (= PGC 32626)
Discovered (Apr 9, 1793) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.6 lenticular galaxy (type E/S0?) in Ursa Major (RA 10 52 17.8, Dec +61 22 47)
Historical Identification: Per Dreyer, NGC 3407 (= GC 2223 = JH 769 = WH III 919, 1860 RA 10 43 20, NPD 27 53.1) is "very faint, very small, round, very small (faint) star near".
Physical Information:

NGC 3408 (= PGC 32616)
Discovered (Apr 8, 1793) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.5 spiral galaxy (type Sc?) in Ursa Major (RA 10 52 11.7, Dec +58 26 17)
Historical Identification: Per Dreyer, NGC 3408 (= GC 2224 = JH 770 = WH III 913, 1860 RA 10 43 21, NPD 30 49.8) is "very faint, considerably small, round, 2 pretty bright stars to south".
Physical Information:

NGC 3409 (= PGC 32470)
Discovered (1886) by
Francis Leavenworth
A magnitude 14.1 spiral galaxy (type Sc?) in Hydra (RA 10 50 20.3, Dec -17 02 37)
Historical Identification: Per Dreyer, NGC 3409 (Leavenworth list II (#426), 1860 RA 10 43 26, NPD 106 17.5) is "extremely faint, small, extended 200°, 2 very faint stars involved".
Physical Information:

NGC 3410 (= PGC 32594)
Discovered (Apr 1, 1878) by
Lawrence Parsons, 4th Earl of Rosse
A magnitude 14.2 spiral galaxy (type S?) in Ursa Major (RA 10 51 53.7, Dec +51 00 23)
Historical Identification: Per Dreyer, NGC 3410 (4th Lord Rosse, 1860 RA 10 43 28, NPD 38 15) is "faint, pretty small, diffuse, 2 arcmin southeast of h771", h771 being NGC 3406.
Physical Information:

Corwin lists a possible companion () at RA 10 51 56.6, Dec +50 59 49

NGC 3411 (=
NGC 3402 = PGC 32479)
Discovered (Mar 25, 1786) by William Herschel (and later listed as NGC 3411)
Also observed (date?) by John Herschel (and later listed as NGC 3411)
Discovered (1880) by Andrew Common (and later listed as NGC 3402)
A magnitude 11.9 elliptical galaxy (type E0?) in Hydra (RA 10 50 26.1, Dec -12 50 42)
Historical Identification: Per Dreyer, NGC 3411 (= GC 2228 = JH 776 = WH III 522, 1860 RA 10 43 29, NPD 102 06.5) is "faint, small, round, a little brighter middle".
Physical Information:

NGC 3412 (= PGC 32508)
Discovered (Apr 8, 1784) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 10.5 lenticular galaxy (type SB0?) in Leo (RA 10 50 53.3, Dec +13 24 44)
Historical Identification: Per Dreyer, NGC 3412 (= GC 2229 = JH 774 = WH I 27, 1860 RA 10 43 29, NPD 75 50.9) is "bright, small, a little extended 135°±, suddenly much brighter middle and nucleus".
Physical Information:

NGC 3413 (= PGC 32543)
Discovered (Dec 7, 1785) by
William Herschel
Also observed (date?) by Heinrich d'Arrest
Also observed (May 7, 1896) by Stephane Javelle
A magnitude 12.2 lenticular galaxy (type S0?) in Leo Minor (RA 10 51 20.7, Dec +32 45 59)
Historical Identification: Per Dreyer, NGC 3413 (= GC 2232 = WH II 493, d'Arrest, 1860 RA 10 43 33, NPD 56 29.5) is "faint, small".
The second IC notes "3413 is = Javelle 1167".
Physical Information:

NGC 3414 (= PGC 32533)
Discovered (Apr 11, 1785) by
William Herschel
Also observed (date?) by John Herschel
A magnitud 11.0 lenticular galaxy (type SB0?) in Leo Minor (RA 10 51 16.2, Dec +27 58 30)
Historical Identification: Per Dreyer, NGC 3414 (= GC 2227 = JH 773 = WH II 362, 1860 RA 10 43 35, NPD 61 17.1) is "bright, pretty large, round, much brighter middle".
Physical Information:

Corwin lists a possible companion () at RA 10 51 13.0, Dec +28 00 22

NGC 3415 (= PGC 32579)
Discovered (Jan 15, 1788) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 12.7 lenticular galaxy (type S0/a?) in Ursa Major (RA 10 51 42.6, Dec +43 42 45)
Historical Identification: Per Dreyer, NGC 3415 (= GC 2225 = JH 772 = WH II 718, 1860 RA 10 43 36, NPD 45 32.8) is "pretty bright, small, very little extended, stellar, 3 small (faint) stars near".
Physical Information:

NGC 3416 (= PGC 32588)
Discovered (Mar 30, 1854) by
R. J. Mitchell
A magnitude 14.5 spiral galaxy (type S?) in Ursa Major. (RA 10 51 48.3, Dec +43 45 51)
Historical Identification: Per Dreyer, NGC 3416 (= GC 2226, 3rd Lord Rosse, 1860 RA 10 43 37, NPD 45 29) is "extremely faint (perhaps faint star?), north of h772", h772 being NGC 3415.
Physical Information:

NGC 3417 (= PGC 32520)
Discovered (Mar 25, 1865) by
Albert Marth
A magnitude 14.6 spiral galaxy (type S?) in Leo (RA 10 51 01.7, Dec +08 28 25)
Historical Identification: Per Dreyer, NGC 3417 (= GC 5538, Marth 207, 1860 RA 10 43 41, NPD 80 48) is "extremely faint, very small, almost stellar".
Physical Information:

NGC 3418 (= PGC 32549)
Discovered (Apr 11, 1785) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.2 lenticular galaxy (type SB0/a?) in Leo Minor (RA 10 51 24.0, Dec +28 06 43)
Historical Identification: Per Dreyer, NGC 3418 (= GC 2230 = JH 775 = WH II 363, 1860 RA 10 43 42, NPD 61 08.8) is "considerably faint, small, round, brighter middle".
Physical Information:

NGC 3419 (= PGC 32535)
Discovered (Jan 14, 1787) by
William Herschel(?)
Discovered (Apr 1, 1864) by Albert Marth
Also observed (Mar 15, 1876) by Wilhelm Tempel
A magnitude 12.5 lenticular galaxy (type SB0/a?) in Leo (RA 10 51 17.7, Dec +13 56 46)
Historical Identification: Per Dreyer, NGC 3419 (= GC 5539, Marth 208, Tempel list I (#??), 1860 RA 10 43 54, NPD 75 18.7) is "faint, very small, round, almost stellar, small (faint) star very near".
Discovery Notes: Dreyer's failure to mention Herschel's supposed observation in the NGC means that it was identified at a later or even far later time; that also suggests that the observation is of uncertain quality, so this entry may involve considerably more information and/or speculation when it is finished. For now, the attribution to Herschel should probably be treated as tentative. Physical Information:

PGC 32540 (= "NGC 3419A")
Not an NGC object but listed here because sometimes called NGC 3419A
A magnitude 14.1 spiral galaxy (type SBbc?) in
Leo (RA 10 51 19.8, Dec +14 01 24)

NGC 3420 (= PGC 32453)
Discovered (1886) by
Francis Leavenworth
Also observed (date?) by Herbert Howe
A magnitude 13.8 spiral galaxy (type SBa?) in Hydra (RA 10 50 09.7, Dec -17 14 33)
Historical Identification: Per Dreyer, NGC 3420 (Leavenworth list II (#427), 1860 RA 10 43 56, NPD 106 28.5) is "extremely faint, very small, round, pretty gradually brighter middle and nucleus, magnitude 8.5 star 6 arcmin to south".
The second IC lists a corrected RA (per Howe) of 10 43 17.
Physical Information:

NGC 3421 (= PGC 32514 =
IC 652)
Discovered (1880) by Andrew Common (and later listed as NGC 3421)
Also observed (date?) by Herbert Howe (while listed as NGC 3421)
Discovered (Apr 19, 1892) by Stephane Javelle (and later listed as IC 652)
A magnitude 13.7 spiral galaxy (type (R)SB(rs)a? pec) in Hydra (RA 10 50 57.6, Dec -12 26 54)
Historical Identification: Per Dreyer, NGC 3421 (Common (#8), 1860 RA 10 43 57, NPD 101 29) is one of "2 nebulae, faint, round", the other being NGC 3422. The second IC says of NGC 3421-22 "Only one seen by Howe, RA 10 44 00, NPD 101 42.4, two suspected north and southwest of it."
Discovery Note: See IC 652 for a discussion of the duplicate listing.
Physical Information: Apparent size 1.7 by 1.4 arcmin.
DSS image of spiral galaxy NGC 3421
Above, a 2.4 arcmin wide closeup of NGC 3421
Below, a 12 arcmin wide region centered on the galaxy, also showing NGC 3422
DSS image of region near spiral galaxy NGC 3421, also showing lenticular galaxy NGC 3422

NGC 3422 (= PGC 32534)
Discovered (1880) by
Andrew Common
Also observed (date?) by Herbert Howe (while listed as NGC 3422)
A magnitude 14.1 lenticular galaxy (type S0/a?) in Crater (RA 10 51 17.4, Dec -12 24 09)
Historical Identification: Per Dreyer, NGC 3422 (Common (#8), 1860 RA 10 43 57, NPD 101 29) is one of "2 nebulae, faint, round", the other being NGC 3421.
The second IC says of NGC 3421-22 "Only one seen by Howe, RA 10 44 00, NPD 101 42.4, two suspected north and southwest of it."
Physical Information:

NGC 3423 (= PGC 32529)
Discovered (Feb 23, 1784) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 11.1 spiral galaxy (type Sc?) in Sextans (RA 10 51 14.3, Dec +05 50 24)
Historical Identification: Per Dreyer, NGC 3423 (= GC 2234 = JH 777 = WH IV 6 = WH II 131, 1860 RA 10 43 58, NPD 83 25.0) is "faint, very large, round, very gradually brighter middle, partially resolved (some stars seen)".
Physical Information:

NGC 3424 (= PGC 32584)
Discovered (Dec 7, 1785) by
William Herschel
Also observed (date?) by John Herschel
Also observed (date?) by Heinrich d'Arrest
A magnitude 12.4 spiral galaxy (type SBb?) in Leo Minor (RA 10 51 46.3, Dec +32 54 02)
Historical Identification: Per Dreyer, NGC 3424 (= GC 2235 = JH 778 = WH II 494, 1860 RA 10 44 00, NPD 56 21.6) is "pretty faint, pretty large, a little extended, southwestern of 3", the second being NGC 3430, but there is no "third", as discussed in the entry for NGC 3430.
Discovery Notes: As discussed in the entry for NGC 3430, d'Arrest's examination of the area near NGC 3424 and 3430 was crucial in proving the nonexistence of the "third" galaxy mentioned in the NGC entries; hence the need to list the date of his observation above.
Physical Information:

NGC 3425 (= PGC 32555 =
NGC 3388)
Discovered (Apr 17, 1784) by William Herschel (and later listed as NGC 3425)
Also observed (1877) by Wilhelm Tempel (and later listed as NGC 3425)
Discovered (1880) by Andrew Common (and later listed as NGC 3388)
A magnitude 13.1 lenticular galaxy (type S0?) in Leo (RA 10 51 25.5, Dec +08 34 02)
Historical Identification: Per Dreyer, NGC 3425 (= GC 2237 = WH III 108, Tempel list I (#??) and list V (#??), 1860 RA 10 44 00, NPD 80 43.0) is "extremely faint, extremely small, round".
Physical Information:

NGC 3426 (= PGC 32577)
Discovered (Mar 23, 1887) by
Lewis Swift
A magnitude 13.2 spiral galaxy (type S?) in Leo (RA 10 51 41.8, Dec +18 28 51)
Historical Identification: Per Dreyer, NGC 3426 (Swift list VI (#37), 1860 RA 10 44 05, NPD 70 46.4) is "pretty faint, small, round, double star to north".
Physical Information:

NGC 3427 (= PGC 32559)
Discovered (1877) by
Wilhelm Tempel
Also observed (Nov 11, 1877) by David Todd
A magnitude 13.2 lenticular galaxy (type S0/a?) in Leo (RA 10 51 26.3, Dec +08 17 55)
Historical Identification: Per Dreyer, NGC 3427 (Tempel list I (#29) & list V (#??), 1860 RA 10 44 10, NPD 81 00.0) is a "nebula, no description".
Physical Information:

NGC 3428 (= PGC 32552 =
NGC 3429)
Discovered (Mar 25, 1865) by Albert Marth (and later listed as NGC 3428)
Discovered (1880) by Andrew Common (and later listed as NGC 3429)
A magnitude 13.1 spiral galaxy (type SBb?) in Leo (RA 10 51 29.5, Dec +09 16 46)
Historical Identification: Per Dreyer, NGC 3428 (= GC 5540, Marth 209, 1860 RA 10 44 10, NPD 79 59) is "very faint, small, a little extended, gradually a little brighter middle".
Physical Information:

NGC 3429 (= PGC 32552 =
NGC 3428)
Discovered (Mar 25, 1865) by Albert Marth (and later listed as NGC 3428)
Discovered (1880) by Andrew Common (and later listed as NGC 3429)
A magnitude 13.1 spiral galaxy (type SBb?) in Leo (RA 10 51 29.5, Dec +09 16 46)
Historical Identification: Per Dreyer, NGC 3429 (Common (#9), 1860 RA 10 44 12, NPD 80 00.0) is "pretty faint, round".
Physical Information: Given the duplicate listing, see NGC 3428 for anything else.

NGC 3430 (= PGC 32614)
Discovered (Dec 7, 1785) by
William Herschel
Also observed (Mar 8, 1828) by John Herschel
Also observed (date?) by Heinrich d'Arrest
A magnitude 11.6 spiral galaxy (type SBc?) in Leo Minor (RA 10 52 11.4, Dec +32 57 02)
Historical Identification: Per Dreyer, NGC 3430 (= GC 2236 = JH 779 = GC 2239 = JH 782 = WH I 118, 1860 RA 10 44 23, NPD 56 18.5) is "pretty bright, large, irregularly extended, gradually brighter middle, 2nd of 3", the first of three being NGC 3424, but there is no "third" (see Discovery Notes).
Discovery Notes: In John Herschel's General Catalog, GC 2235, 2236 and 2239 were listed as the southwestern, 2nd and northeastern of three nebulae, but in Dreyer's 1877 Supplement to the GC he states that GC 2239 is to be struck out, as per d'Arrest's discussion of the region, it is a duplicate of GC 2236; hence the line equating the two in the NGC listing. As a result, there are only two galaxies in "the line of three" discussed in the GC, and the reference to "southwestern of 3" for NGC 3424 and "2nd of 3" for NGC 3430 is an inadvertent carry-over of the incorrect description in the GC.
Physical Information:

NGC 3431 (= PGC 32531)
Discovered (Jan 5, 1887) by
Francis Leavenworth
A magnitude 13.6 spiral galaxy (type Sb?) in Crater (RA 10 51 15.0, Dec -17 00 29)
Historical Identification: Per Dreyer, NGC 3431 (Leavenworth list II (#428), 1860 RA 10 44 26, NPD 106 16.5) is "extremely faint, small, extended 130°, gradually brighter middle".
Physical Information:

NGC 3432 (= PGC 32643, and with
PGC 32617 = Arp 206)
Discovered (Mar 19, 1787) by William Herschel
Also observed (Mar 11, 1831) by John Herschel
A magnitude 11.3 spiral galaxy (type SB(s)m?) in Leo Minor (RA 10 52 31.2, Dec +36 37 09)
Historical Identification: Per Dreyer, NGC 3432 (= GC 2238 = JH 780 = WH I 172, 1860 RA 10 44 36, NPD 52 38.5) is "pretty bright, pretty large, very much extended 40°, double star close to southwest". The position precesses to RA 10 52 29.5, Dec +36 36 59, right on the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 615 km/sec (and H0 = 70 km/sec/Mpc), NGC 3432 is almost 30 million light-years away, in good agreement with redshift-independent distance estimates of about 25 to 55 million light-years. Given that and its apparent size of about 6.5 by 1.0 arcmin (from the images below), it is about 55 thousand light-years across. Probably due to a relatively recent encounter with another galaxy (perhaps its southwestern companion), NGC 3432 is filled with numerous regions of star formation. With that apparent companion, PGC 32617, it is listed as Arp 206, as an example of a galaxy with material ejected from the nucleus. Note: The galaxy type is reasonably certain, but since it is almost exactly edge-on to our line of sight, it might be given a slightly different classification if we could see it face-on, hence the question mark added to its stated type.
SDSS image of region near spiral galaxy NGC 3432
Above, a 12 arcmin wide SDSS image centered on NGC 3432, also showing PGC 32617
Below, a 6.5 arcmin wide SDSS image of Arp 206
SDSS image of region near spiral galaxy NGC 3432
Below, a 2.5 by 3.0 arcmin wide HST more or less 'natural-color' image of part of the galaxy
(Image Credit Hubble Legacy Archive, Fabian RRRR)
HST image of part of spiral galaxy NGC 3432
Below, a 2.4 by 2.6 arcmin wide HST false-color image of activity in the galaxy
(Image Credit ESA/Hubble/NASA, A. Filippenko, R. Jansen)
HST image of part of spiral galaxy NGC 3432

PGC 32617 (with
NGC 3432 = Arp 206)
Not an NGC object but listed here as part of Arp 206
A magnitude 16.0(?) irregular galaxy (type I?) in Leo Minor (RA 10 52 16.8, Dec +36 35 41)
Physical Information: Based on a recessional velocity of 765 km/sec (and H0 = 70 km/sec/Mpc), PGC 32617 is about 35 million light-years away, in reasonable agreement with the distance of its apparent companion, NGC 3432 (though their Hubble distances are a little different, they are very likely to be at nearly the same distance, and simply moving at 150 or so km/sec relative to each other). Given that and its apparent size of about 1.15 by 0.75 arcmin (from the image below), it is about 12 to 15 thousand light-years across, making it a dwarf galaxy.
SDSS image of dwarf irregular galaxy PGC 32617, part of Arp 206
Above, a 1.5 arcmin wide SDSS image of PGC 32617; for wider-field images see NGC 3432

NGC 3433 (= PGC 32605)
Discovered (Mar 11, 1784) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 11.6 spiral galaxy (type Sc?) in Leo (RA 10 52 03.9, Dec +10 08 54)
Historical Identification: Per Dreyer, NGC 3433 (= GC 2240 = JH 783 = WH III 20, 1860 RA 10 44 43, NPD 79 06.0) is "very faint, very large, round, very gradually brighter middle".
Physical Information:

NGC 3434 (= PGC 32595)
Discovered (Jan 27, 1786) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 12.0 spiral galaxy (type Sb?) in Leo (RA 10 51 58.0, Dec +03 47 31)
Historical Identification: Per Dreyer, NGC 3434 (= GC 2241= JH 784 = WH III 497, 1860 RA 10 44 44, NPD 85 28.0) is "faint, pretty small, round, very gradually a little brighter middle".
Physical Information:

NGC 3435 (= PGC 32786)
Discovered (Apr 9, 1793) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.2 spiral galaxy (type Sb?) in Ursa Major (RA 10 54 48.3, Dec +61 17 24)
Historical Identification: Per Dreyer, NGC 3435 (= GC 2242 = JH 781 = WH II 887, 1860 RA 10 44 55, NPD 27 58.4) is "considerably faint, pretty small, a little extended, very gradually brighter middle".
Physical Information:

NGC 3436 (= PGC 32633)
Discovered (Nov 30, 1877) by
David Todd
A magnitude 14.1 lenticular galaxy (type S0?) in Leo (10 52 27.5, Dec +08 05 39)
Historical Identification: Per Dreyer, NGC 3436 (Todd (#6), 1860 RA 10 44, NPD 81 18) is "extremely small".
Physical Information:

NGC 3437 (= PGC 32648)
Discovered (Mar 12, 1784) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 12.1 spiral galaxy (type SBc?) in Leo (RA 10 52 35.8, Dec +22 56 03)
Historical Identification: Per Dreyer, NGC 3437 (= GC 2243 = JH 786 = WH II 47, 1860 RA 10 45 01, NPD 66 19.6) is "pretty bright, pretty large, a little extended 120°, gradually brighter middle".
Physical Information:

NGC 3438 (= PGC 32638)
Discovered (Mar 25, 1865) by
Albert Marth
A magnitude 13.4 spiral galaxy (type S?) in Leo (RA 10 52 26.0, Dec +10 32 50)
Historical Identification: Per Dreyer, NGC 3438 (= GC 5541, Marth 210, 1860 RA 10 45 06, NPD 78 43) is "very faint, extremely small, almost stellar".
Physical Information:

NGC 3439 (= PGC 32634)
Discovered (Mar 25, 1865) by
Albert Marth
A magnitude 13.9 elliptical galaxy (type E3?) in Leo (RA 10 52 25.7, Dec +08 33 27)
Historical Identification: Per Dreyer, NGC 3439 (= GC 5542, Marth 211, 1860 RA 10 45 06, NPD 80 43) is "most extremely faint, very small, almost stellar".
Physical Information:

NGC 3440 (= PGC 32714)
Discovered (Apr 8, 1793) by
William Herschel
Also observed (date?) by John Herschel
A magnitude 13.2 spiral galaxy (type SBb?) in Ursa Major (RA 10 53 49.5, Dec +57 07 07)
Historical Identification: Per Dreyer, NGC 3440 (= GC 2244 = JH 785 = WH III 914, 1860 RA 10 45 11, NPD 32 08.5) is "very faint, small, a little extended".
Physical Information:

NGC 3441 (= PGC 32642)
Discovered (Apr 6, 1882) by
Edward Holden
A magnitude 13.6 spiral galaxy (type Sc?) in Leo (RA 10 52 31.1, Dec +07 13 30)
Historical Identification: Per Dreyer, NGC 3441 (Holden (#2), 1860 RA 10 45 13, NPD 82 03) is "pretty bright".
Physical Information:

NGC 3442 (= PGC 32679)
Discovered (Mar 25, 1884) by
Édouard Stephan
A magnitude 13.4 spiral galaxy (type Sa?) in Leo Minor (RA 10 53 08.1, Dec +33 54 37)
Historical Identification: Per Dreyer, NGC 3442 (Stephan list XIII (#59), 1860 RA 10 45 20, NPD 55 20.8) is "faint, very small, round, much brighter middle, mottled but not resolved?"
Physical Information:

NGC 3443 (= PGC 32671)
Discovered (Apr 24, 1887) by
Lewis Swift
A magnitude 13.1 spiral galaxy (type Scd?) in Leo (RA 10 53 00.0, Dec +17 34 27)
Historical Identification: Per Dreyer, NGC 3443 (Swift list VI (#38), 1860 RA 10 45 24, NPD 71 49.3) is "most extremely faint, very small, round".
Physical Information:

NGC 3444 (= PGC 32670)
Discovered (Mar 25, 1865) by
Albert Marth
A magnitude 14.7 spiral galaxy (type Sbc?) in Leo (RA 10 52 59.4, Dec +10 12 38)
Historical Identification: Per Dreyer, NGC 3444 (= GC 5543, Marth 212, 1860 RA 10 45 39, NPD 79 04) is "extremely faint, very small, pretty much extended".
Physical Information:

NGC 3445 (=
Arp 24)
(= PGC 32772 = UGC 6021 = CGCG 291-011 = MCG +10-16-023)

Discovered (Apr 8, 1793) by William Herschel
Also observed (Feb 9, 1831) by John Herschel
Also observed (Mar 30, 1856) by R. J. Mitchell
A magnitude 12.7 spiral galaxy (type SAB(s)m) in Ursa Major (RA 10 54 35.5, Dec +56 59 27)
Historical Identification: Per Dreyer, NGC 3445 (= GC 2245 = JH 787 = WH I 267, 1860 RA 10 45 58, NPD 32 16.3) is "considerably bright, pretty large, irregularly round, very gradually a little brighter middle, 10th magnitude star 2 arcmin to northeast." The position precesses to RA 10 54 35.7, Dec +56 59 05, slightly below the southern rim of the nucleus of the galaxy listed above but well within its overall outline, the description is a perfect fit and there is nothing comparable nearby, so the identification is certain.
Discovery Note: As pointed out by Gottlieb, Mitchell observed the nebula with the 3rd Lord Rosse's 72-inch "Leviathan", and among other things noted (and sketched) a "streak south-following", which is obviously the physically interacting companion, PGC 32784. This means that though not part of NGC 3445, or (as noted in the next paragraph) of Arp 24, PGC 32784 is in Corwin's list of "notngc" objects — objects that were discovered prior to the publication of the NGC, but never became part of it or its supplements.
Usage By The Arp Atlas: NGC 3445 is used by the Arp Atlas as an example of a one-armed spiral galaxy. Though it is probably interacting with PGC 32784, that galaxy is not part of Arp 24, but merely a companion of its larger neighbor.
Physical Information: Based on a recessional velocity relative to the Cosmic Microwave Background radiation of 2210 km/sec (and H0 = 70 km/sec/Mpc), NGC 3445 is about 100 to 105 million light-years away, in good agreement with redshift-independent distance estimates of about 55 to 105 million light-years. Given that and its apparent size of about 1.45 by 1.25 arcmin (from the images below), the galaxy is about 40 to 45 thousand light-years across. (Note: The third galaxy shown in the images below, PGC 2554198, is roughly 635 million light-years from us, and is therefore a much more distant background object.)
SDSS image of region near NGC 3445, which is Arp 24, also showing PGC 32784 and PGC 2554198
Above, a 12 arcmin wide SDSS image centered on NGC 3445, also showing PGC 32784 and PGC 2554198
Below, a 2.4 arcmin wide SDSS image of the three galaxies
SDSS image of NGC 3445, PGC 32784 and PGC 2554198
Below, a 2.3 by 1.8 arcmin wide image of the three galaxies (Image Credit Hubble Legacy Archive, Judy Schmidt)
HST image of spiral galaxy NGC 3445, which is Arp 24, also showing PGC 32784 and PGC 2554198
Below, a 1.6 arcmin wide image of NGC 3445 (Image Credit as above)
HST image of spiral galaxy NGC 3445, which is Arp 24

PGC 32784
(= MCG +10-16-024, and not part of
Arp 24)
Not an NGC object but listed here because a probable companion of NGC 3445
and because often misidentified as part of Arp 24
and because it is one of a number of objects discovered before the publication of the NGC

Discovered (Mar 30, 1856) by R. J. Mitchell
A magnitude 16.5(?) spiral galaxy (type Sm/Im?) in Ursa Major (RA 10 54 44.2, Dec +56 58 58)
Discovery Note: As noted in the entry for NGC 3445, Mitchell noted (and sketched) the faint streak to the southeast of the larger galaxy, but presumably because no position was published for it, it was not included in either the GC or NGC, and wasn't cataloged until over a century later (as MCG +10-16-024). As a result, it is one of the numerous objects in Corwin's "notngc" list of objects discovered before the publication of the NGC, but not included in that catalog or its supplements.
(Non-)Usage By The Arp Atlas: Most references (e.g., LEDA and NED) list PGC 32784 as part of Arp 24 (= NGC 3445); however, although it is probably an interacting companion of that galaxy, there is absolutely nothing in Arp's catalog to justify its being considered part of the Arp object. Arp 24 is classified as a one-armed spiral galaxy (NGC 3445), but in cases where a small second galaxy was involved, Arp classified the pair as a spiral galaxy with a small high or low surface brightness companion. Since he did not classify Arp 24 as a pair of any sort, PGC 32784 cannot be part of Arp 24, hence the warning about that in the title for this entry.
Physical Information: There is some disagreement about the recessional velocity of PGC 32784. LEDA and SIMBAD list values (relative to the Cosmic Microwave Background) of about 2085 and 2045 km/sec, while NED lists a value of only 1900 km/sec, despite stating that this is a member of a pair with NGC 3445, which has a recessional velocity of 2210 km/sec. The first two values would suggest that the two galaxies are a pair, in which case they would have to be at the same distance, and any difference in their recessional velocities would be due to their "peculiar velocities" (random motions relative to their neighbors, unrelated to the Hubble Flow recessional velocity). The HST image showing both galaxies (below) shows what appears to be a filament connecting the pair, also suggesting that they are a physical pair. Given that, I have chosen to ignore the disagreement in the recessional velocities, and to just assume that PGC 32784 is at the same distance (roughly 100 to 105 million light-years away) from us as NGC 3445. Given that and its apparent size of about 0.6 by 0.2 arcmin (from the images below), PGC 32784 is about 18 thousand light-years across (give or take a thousand or so).
Classification Note: Most references list this galaxy as type Sm (with or without a question mark), but SIMBAD lists it as Sm/Im? There is nothing in the images on this page to indicate which is more likely to be correct, so I have used the double classification from SIMBAD.
SDSS image of NGC 3445, which is Arp 24, also showing spiral/irregular galaxy PGC 32784 and PGC 2554198
Above, a 2.4 arcmin wide SDSS image of NGC 3445, also showing PGC 32784 and PGC 2554198
Below, a 2.3 by 1.8 arcmin wide image of the three galaxies (Image Credit Hubble Legacy Archive, Judy Schmidt)
HST image of NGC 3445, which is Arp 24, also showing spiral/irregular galaxy PGC 32784 and PGC 2554198
Below, a 0.75 arcmin wide image of PGC 32784 (Image Credit as above)
HST image of spiral/irregular galaxy PGC 32784

NGC 3446 (= ESO 264-SC045)
Discovered (Mar 15, 1836) by
John Herschel
A magnitude ? open cluster in Vela (RA 10 52 17.0, Dec -45 09 24)
Historical Identification: Per Dreyer, NGC 3446 (= GC 2246 = JH 3301, 1860 RA 10 45 59, NPD 134 24.4) is a "cluster, pretty large, poor, a little compressed, irregular figure, stars from 9th to 13th magnitude".
Physical Information:

NGC 3447 (= PGC 32694)
Discovered (Mar 18, 1836) by
John Herschel
A magnitude 13.3 spiral galaxy (type SBdm? pec) in Leo (RA 10 53 24.0, Dec +16 46 21)
Historical Identification: Per Dreyer, NGC 3447 (= GC 2247 = JH 3300, 1860 RA 10 46 00, NPD 72 29.5) is "extremely faint, very large, very gradually very little brighter middle, bright double star to southwest".
Physical Information:

PGC 32700 (= "NGC 3447A")
Not an NGC object but listed here because sometimes called NGC 3447A
A magnitude 12.5 irregular galaxy (type IBm? pec) in
Leo (RA 10 53 30.1, Dec +16 47 06)

NGC 3448 (= PGC 32774, and with PGC 32740 =
Arp 205)
Discovered (Apr 17, 1789) by William Herschel
Also observed (Feb 10, 1831) by John Herschel
A magnitude 11.6 irregular galaxy (type IB0?) in Ursa Major (RA 10 54 38.7, Dec +54 18 19)
Historical Identification: Per Dreyer, NGC 3448 (= GC 2248 = JH 788 = WH I 233, 1860 RA 10 46 10, NPD 34 57.1) is "bright, pretty large, much extended 67°.0, gradually brighter middle".
Physical Information: Based on a recessional velocity of 1350 km/sec, NGC 3448 is about 65 million light-years away, in fair agreement with a redshift-independent distance estimate of 80 million light-years. (Its apparent companion, PGC 32740, has a recessional velocity of 1495 km/sec, which corresponds to a distance of 70 million light-years.) Given that and its apparent size of 2.6 by 1.0 arcmin, the main galaxy is about 50 thousand light-years across, and the entire complex listed as Arp 205, which is 8.0 by 1.1 arcmin, is about 150 thousand light-years across. Used by the Arp Atlas as an example of a galaxy (NGC 3448) with material (PGC 32740) ejected from its nucleus.
Classification Note: Steinicke lists this as type S0/a (lenticular).
SDSS image of region near irregular galaxy NGC 3448, also showing PGC, with which is it comprises Arp 205
Above, a 12 arcmin wide SDSS image centered on NGC 3448, also showing PGC 32740
Below, a 3 arcmin wide SDSS image of the galaxy
SDSS image of irregular galaxy NGC 3448, which is part of Arp 205

NGC 3449 (= PGC 32666 = ESO 376-025)
Discovered (Apr 29, 1834) by
John Herschel
A magnitude 11.7 spiral galaxy (type SBab?) in Antlia (RA 10 52 53.7, Dec -32 55 39)
Historical Identification: Per Dreyer, NGC 3449 (= GC 2249 = JH 3302, 1860 RA 10 46 20, NPD 122 11.0) is "faint, small, round, 6.7 magnitude star to southeast".
Physical Information:
Celestial Atlas
(NGC 3350 - 3399) ←NGC Objects: NGC 3400 - 3449→ (NGC 3450 - 3499)