Celestial Atlas
(NGC 5450 - 5499) ←     NGC Objects: NGC 5500 - 5549 Link for sharing this page on Facebook     → (NGC 5550 - 5599)
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Page last updated Feb 7, 2016
Compared to Steinicke database updates, added all GC/Dreyer information, Corwin positions
WORKING 5524, 5527: Dealing with specific problems (also, check all Corwin notes)
WORKING 5548: Checking historical IDs, adding pix, physical data
notngc = PGC 50709, PGC 50952, IC 990<

NGC 5500 (= PGC 50588)
Discovered (May 12, 1787) by
William Herschel
A magnitude 13.3 elliptical galaxy (type E2?) in Bo÷tes (RA 14 10 15.2, Dec +48 32 46)
Historical Identification: Per Dreyer, NGC 5500 (= GC 3804, WH III 674, 1860 RA 14 05 06, NPD 40 46.2) is "considerably faint, considerably small, irregularly round". The position precesses to RA 14 10 22.9, Dec +48 34 07, about 1.8 arcmin northeast of 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 1915 km/sec, NGC 5500 is about 90 million light years away. Given that and its apparent size about 0.9 by 0.7 arcmin it is about 20 to 25 thousand light years across.
SDSS image of region near elliptical galaxy NGC 5500
Above, a 12 arcmin wide SDSS image centered on NGC 5500
Below, a 1.4 arcmin wide SDSS image of the galaxy
SDSS image of elliptical galaxy NGC 5500

NGC 5501 (= PGC 50724)
Discovered (Apr 13, 1828) by
John Herschel
A magnitude 13.5 lenticular galaxy (type (R)SA(r)0/a?) in Virgo (RA 14 12 20.2, Dec +01 16 21)
Historical Identification: Per Dreyer, NGC 5501 (= GC 3805, JH 1756, 1880 RA 14 05 13, NPD 88 05.1) is "very faint, small, partially resolved, some stars seen". The position precesses to RA 14 12 20.5, Dec +01 15 19, about 1 arcmin nearly due south of the galaxy listed above, the description is a reasonable fit and there is nothing else nearby so the identification is certain.
Physical Information: Based on a recessional velocity of 7565 km/sec, a straightforward calculation indicates that NGC 5501 is about 350 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 340 million light years away at the time the light by which we see it was emitted, about 345 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.7 by 0.5 arcmin, the galaxy is about 70 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5501
Above, a 12 arcmin wide SDSS image centered on NGC 5501
Below, a 1 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5501

WORKING HERE
PGC 50709 (UGC 09084 in Corwin's notngc)
Not an NGC object but listed here because discovered prior to the completion of the NGC
Discovered (probably about 1883) by
Wilhelm Tempel
A magnitude 14(?) spiral galaxy (type (R)Sb?) in Bo÷tes (RA 14 12 12.7, Dec +08 39 43)
Historical Identification: (1860 RA 14 05 18, NPD 80 40.7). Discussion of discovery and failure to include in NGC is related to NGC 5482.
Physical Information: Vr 7235 km/sec, z 0.024127, 74.6 to 86.9 Mpc, about 1.1 by 0.9 arcmin??
Above, a 12 arcmin wide SDSS image centered on PGC 50709
Below, a ? arcmin wide SDSS image of the galaxy

NGC 5502 (=
NGC 5503 = PGC 50508)
Discovered (May 9, 1885) by Edward Swift (and later listed as NGC 5502)
Discovered (May 11, 1885) by Lewis Swift (and later listed as NGC 5503)
A magnitude 15.3 lenticular galaxy (type (R)S0/a?) in Ursa Major (RA 14 09 34.0, Dec +60 24 34)
Historical Identification: Per Dreyer, NGC 5502 (Swift list I (#29), 1860 RA 14 05 20, NPD 28 53.6) is "most extremely faint, pretty small, round, very difficult, between 2 stars". The position precesses to RA 14 09 33.8, Dec +60 26 41, about 2.1 arcmin due north of the galaxy listed above, the description of the galaxy and the starfield fits and there is nothing else nearby, so the identification is certain. For a discussion of the double listing see NGC 5503.
Physical Information: Based on a recessional velocity of 8830 km/sec, a straightforward calculation indicates that NGC 5502 is about 410 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 395 to 400 million light years away at the time the light by which we see it was emitted, about 400 to 405 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.45 by 0.25 arcmin, the galaxy is about 50 to 55 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5502
Above, a 12 arcmin wide SDSS image centered on NGC 5502
Below, a 0.75 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5502

NGC 5503 (=
NGC 5502 = PGC 50508)
Discovered (May 9, 1885) by Edward Swift (and later listed as NGC 5502)
Discovered (May 11, 1885) by Lewis Swift (and later listed as NGC 5503)
A magnitude 15.3 lenticular galaxy (type (R)S0/a?) in Ursa Major (RA 14 09 34.0, Dec +60 24 34)
Historical Identification: Per Dreyer, NGC 5503 (Swift list I (#30), 1860 RA 14 05 27, NPD 28 56.1) is "most extremely faint, very small, round, very difficult, 2 stars near". The position precesses to RA 14 09 40.9, Dec +60 24 12, just under an arcmin east southeast of the galaxy listed above, the description of the galaxy and the starfield fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Since the Swifts' descriptions and positions are nearly identical, it is surprising that neither Lewis Swift nor Dreyer realized that Swift list I #29 and #30 might be the same object; but apparently the difference in position, though only a little over 2 arcmin, was great enough to confuse them, leading to the duplicate entry.
Physical Information: Given the duplicate entry, see NGC 5502 for anything else.

NGC 5504 (= PGC 50718)
Discovered (Jun 7, 1880) by
╔douard Stephan
A magnitude 13.0 spiral galaxy (type SAB(s)bc?) in Bo÷tes (RA 14 12 15.8, Dec +15 50 31)
Historical Identification: Per Dreyer, NGC 5504 (Stephan list XI (#23), 1860 RA 14 05 34, NPD 73 29.9) is "very faint, very little extended, very little brighter middle". The position precesses to RA 14 12 15.4, Dec +15 50 32, right on the galaxy listed above, so the identification is certain.
Discovery Notes: Stephan published several papers in 1881, but everything in the shorter papers is collected in A.N. 2390, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 5250 km/sec, NGC 5504 is about 245 million light years away. Given that and its apparent size of about 1.2 by 1.15 arcmin, it is about 85 thousand light years across.
SDSS image of region near spiral galaxy NGC 5504, also showing IC 4383 and PGC 50713
Above, a 12 arcmin wide SDSS image centered on NGC 5504, also showing IC 4383 and PGC 50713
Below, a 1.6 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5504

IC 4383 (= PGC 50716 = PGC 50730 = "NGC 5504B")
Listed here because sometimes called NGC 5504B, instead of by its IC designation
Discovered (May 26, 1894) by Guillaume Bigourdan
A magnitude 14.5 spiral galaxy (type SAB(s)b? pec?) in Bo÷tes (RA 14 12 12.7, Dec +15 52 08)
See IC 4383 for anything else.

PGC 50713 (= "NGC 5504C")
Not an NGC object but listed here since sometimes called NGC 5504C
A magnitude 15.7 spiral galaxy (type Sdm?) in
Bo÷tes (RA 14 12 16.0, Dec +15 52 48)
Historical Misidentification: Often inexplicably confused with IC 4383, which see.
Physical Information: Based on a recessional velocity of 5250 km/sec, PGC 50713 is about 245 million light years away. Given that and its apparent size of about 0.95 by 0.35 arcmin, it is about 65 to 70 thousand light years across.
SDSS image of spiral galaxy PGC 50713, which is sometimes called NGC 5504C, and often misidentified as IC 4383
Above, a 1.0 arcmin wide SDSS image of PGC 50713; for a wider-field image see NGC 5504

NGC 5505 (= PGC 50745)
Discovered (Jun 6, 1886) by
Lewis Swift
A magnitude 13.2 spiral galaxy (type SBab? pec?) in Bo÷tes (RA 14 12 31.7, Dec +13 18 17)
Historical Identification: Per Dreyer, NGC 5505 (Swift list III (#79), 1860 RA 14 05 43, NPD 76 03.5) is "very faint, pretty small, between a star and a double star". The position precesses to RA 14 12 29.1, Dec +13 16 57, about 1.5 arcmin north northeast of 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 4265 km/sec, NGC 5505 is about 195 to 200 million light years away. Given that and its apparent size of about 0.9 by 0.7 arcmin, it is about 50 to 55 thousand light years across. Its unusually bright nucleus suggests that it may be a starburst or Seyfert galaxy.
SDSS image of region near spiral galaxy NGC 5505
Above, a 12 arcmin wide SDSS image centered on NGC 5505
Below, a 1 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5505

NGC 5506 (= PGC 50782)
Discovered (Apr 15, 1787) by
William Herschel
Also observed (Apr 15, 1828) by John Herschel
A magnitude 11.9 spiral galaxy (type Sa? pec) in Virgo (RA 14 13 14.9, Dec -03 12 27)
Historical Identification: Per Dreyer, NGC 5506 (= GC 3806, JH 1757, WH II 687, 1860 RA 14 05 59, NPD 92 32.7) is "pretty bright, large, extended 20░▒, little brighter middle". The position precesses to RA 14 13 14.3, Dec -03 12 11, on the northern rim of the galaxy listed above, the description fits and the only other nearby object is accounted for by NGC 5507, so the identification is certain.
Physical Information: Based on a recessional velocity of 1855 km/sec, NGC 5506 is about 85 million light years away, in good agreement with redshift-independent distance estimates of 55 to 95 million light years. Given that and its apparent size of about 3.5 by 1.1 arcmin (including faint outer extensions), it is about 85 to 90 thousand light years across. It is listed as a Seyfert galaxy (type 1.9), and is a radio-wave and X-ray emitter.
SDSS image of region near spiral galaxy NGC 5506, also showing NGC 5507
Above, a 12 arcmin wide SDSS image centered on NGC 5506, also showing NGC 5507
Below, a 4.2 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5506
Below, a 3.6 arcmin wide image of the galaxy (Image Credit & © Carnegie-Irvine Galaxy Survey; used by permission)
Carnegie-Irvine Galaxy Survey image of spiral galaxy NGC 5506
Below, a 1.7 by 1.2 arcmin wide image of the western side of the galaxy
("Raw" Hubble Legacy Archive image; almost every starlike object is due to cosmic rays hitting the CCD)
Carnegie-Irvine Galaxy Survey image of spiral galaxy NGC 5506

NGC 5507 (= PGC 50786)
Discovered (Apr 15, 1787) by
William Herschel
Also observed (Apr 15, 1828) by John Herschel
Also observed (Mar 29, 1856) by R. J. Mitchell
A magnitude 12.5 lenticular galaxy (type SA0(r)?) in Virgo (RA 14 13 19.9, Dec -03 08 56)
Historical Identification: Per Dreyer, NGC 5507 (= GC 3807 = GC 3808, JH 1758, WH IV 49, (3rd Lord Rosse), 1860 RA 14 06 06, NPD 92 29.5) is "considerably faint, small, round, stellar". The position precesses to RA 14 13 21.2, Dec -03 08 59, within the eastern outline of the galaxy listed above, the description fits and the only other nearby object is accounted for by NGC 5506, so the identification is certain.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by R. J. Mitchell, as shown above. GC 3807's description of the observation by "Lord Rosse" says his "nova" is 3 arcmin from JH 1757 (= NGC 5506), which agrees with the position for GC 3808, hence Dreyer's equating the two entries in his 1877 Supplement to the GC and in the NGC.
Physical Information: Based on a recessional velocity of 1850 km/sec, NGC 5507 is about the same 85 million light year distance as its neighbor, in fair agreement with a single redshift-independent distance estimate of about 110 million light years. Given that and its apparent size of about 1.5 by 0.75 arcmin, it is about 35 to 40 thousand light years across. Although NGC 5506 and 5507 are probably at about the same distance and therefore likely to be gravitationally interacting, NGC 5507 is radio and X-ray quiet, and save for its central ring shows no structural peculiarities related to the possible interaction.
SDSS image of region near lenticular galaxy NGC 5507, also showing NGC 5506
Above, a 12 arcmin wide SDSS image centered on NGC 5507, also showing NGC 5506
Below, a 2 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5506

NGC 5508 (= PGC 50741)
Discovered (Apr 20, 1882) by
╔douard Stephan
A magnitude 13.8 spiral galaxy (type S(rs)b? pec) in Bo÷tes (RA 14 12 29.0, Dec +24 38 08)
Historical Identification: Per Dreyer, NGC 5508 (Stephan list XII (#62), 1860 RA 14 06 06, NPD 64 42.4) is "extremely faint, extremely small, round, little brighter middle". The position precesses to RA 14 12 29.7, Dec +24 38 05, well within the eastern outline of the galaxy listed above, the description is reasonable and there is nothing else nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1883, but everything in the shorter papers is collected in A. N. 2502, so I have used the reference number from that paper.
Physical Information: The galaxy is obviously a spiral, but for some reason seems to be listed everywhere as a lenticular galaxy. Based on a recessional velocity of 11410 km/sec, a straightforward calculation indicates that NGC 5508 is about 530 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 505 to 510 million light years away at the time the light by which we see it was emitted, about 515 to 520 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.9 by 1.5 arcmin (including its faint outer arms), the galaxy is about 280 thousand light years across. This is an exceptionally large size for a spiral, and if correct would make it ten or twenty times more massive than our Milky Way galaxy.
SDSS image of region near spiral galaxy NGC 5508, also showing PGC 50725, which is sometimes misidentified as NGC 5509
Above, a 12 arcmin wide SDSS image centered on NGC 5508, also showing PGC 50725, which see
Below, a 2.4 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5508

NGC 5509 (= PGC 50751)
Discovered (Jun 10, 1887) by
Guillaume Bigourdan
A magnitude 14.1 lenticular galaxy (type E/S0?) in Bo÷tes (RA 14 12 39.6, Dec +20 23 13)
Historical Identification: Per Dreyer, NGC 5509 (Bigourdan (list II #71), 1860 RA 14 06 09, NPD 68 41) is "very faint, small, round, stellar nucleus". The position precesses to RA 14 12 40.9, Dec +20 39 29, but there is nothing there. However (per Corwin), this is due to an error in Bigourdan's list in the Comptes Rendu paper used as a reference by Dreyer. Bigourdan's "big list", published years later, shows the position of and offsets from his comparison star, and reduces as follows: The comparison stars are listed as being 45 seconds of time east and between 17.2 and 19 arcmin south (in 1900 coordinates) of BD+21 2625, but the offset from the comparison star to the nebula is the same for both stars, so they must actually have been the same star, less accurately measured than usual for Bigourdan. BD+21 2625 = HD 124270 has a J2000 position of RA 14 12 10.7, Dec +20 38 34, with a proper motion of -0.0275 arcsec/yr in RA and -0.02162 arcsec/yr in Dec, so in 1887 the star would have been at J2000 RA 14 12 10.9, Dec +20 38 36, which precesses to (1900) RA 14 07 30.8, Dec +21 06 47. That places Bigourdan's comparison star at (1900) RA 14 08 15.8, and between Dec +20 49 35 and +20 47 47. This precesses to somewhere between J2000 RA 14 12 56.1, Dec +20 21 27 and J2000 14 12 56.2, Dec +20 19 39. The only reasonably bright star in that region is a magnitude 12.4 star at J2000 14 12 55.5, Dec +20 20 41. The proper motion of that star does not appear to be known, but its present position precesses to (1900) RA 14 08 15.2, Dec +20 48 49, close to Bigourdan's position of (1900) RA 14 08 17, Dec +20 48, thereby confirming its identification as his comparison star. Adding his average offset to the nebula (-16.1 seconds of right ascension and +2' 33" of declination), that should be at (1900) RA 14 07 59.1, Dec +20 51 22, which precesses to J2000 RA 14 12 39.4, Dec +20 23 13, practically dead center on the galaxy listed above. Given that and the lack of anything else in the region save for the galaxy corresponding to NGC 5508, the identification of PGC 50751 as NGC 5509 is certain.
Discovery Notes: Despite the certainty that PGC 50751 is NGC 5509, several references misidentify PGC 50725 as that NGC object; so it is discussed immediately below.
Physical Information: Based on a recessional velocity of 8560 km/sec, a straightforward calculation indicates that NGC 5509 is about 395 to 400 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 385 million light years away at the time the light by which we see it was emitted, about 390 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.9 by 0.5 arcmin, the galaxy is about 100 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5509
Above, a 12 arcmin wide SDSS image centered on NGC 5509
Below, a 1.5 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5509

PGC 50725 (not =
NGC 5509)
Not an NGC object but listed here since sometimes misidentified as NGC 5509
A magnitude 15.5(?) spiral galaxy (type SB(s)b? pec) in Bo÷tes (RA 14 12 15.7, Dec +24 39 48)
Historical Misidentification: For reasons unknown to me, this object is sometimes misidentified as NGC 5509; but as shown in the discussion of that object, it must be PGC 50751. Hence this warning about the mistake.
Physical Information: Based on a recessional velocity of 15900 km/sec, a straightforward calculation indicates that PGC 50725 is about 740 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 695 million light years away at the time the light by which we see it was emitted, about 715 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.45 by 0.4 arcmin, the galaxy is about 90 thousand light years across.
SDSS image of region near spiral galaxy PGC 50725, which is sometimes misidentified as NGC 5509, also showing NGC 5508
Above, a 12 arcmin wide SDSS image of PGC 50725, also showing NGC 5508
Below, a 0.6 arcmin wide SDSS image of the galaxy sometimes misidentified as NGC 5509
SDSS image of region near spiral galaxy PGC 50725, which is sometimes misidentified as NGC 5509

NGC 5510 (= PGC 50807)
Discovered (1886) by
Ormond Stone
A magnitude 13.4 irregular galaxy (type IB(s)m? pec) in Virgo (RA 14 13 37.3, Dec -17 59 01)
Historical Identification: Per Dreyer, NGC 5510 (Ormond Stone list I (#201), 1860 RA 14 06 20, NPD 107 18.5) is "very faint, small, round, gradually brighter middle". The first IC lists a corrected RA (per Ormond Stone) of 14 05 55. The corrected position precesses to RA 14 13 37.2, Dec -17 57 58, just over an arcmin nearly due north of 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 1440 km/sec, NGC 5510 is about 65 to 70 million light years away. Given that and its apparent size of about 1.3 by 1.3 arcmin, it is about 25 thousand light years across.
SDSS image of region near irregular galaxy NGC 5510
Above, a 12 arcmin wide SDSS image centered on NGC 5510
Below, a 1.6 arcmin wide SDSS image of the galaxy
SDSS image of irregular galaxy NGC 5510

NGC 5511 (= PGC 50771)
Discovered (May 10, 1883) by
George Hough
Not seen (May 13, 1896) by Guillaume Bigourdan
A magnitude 14.5 spiral galaxy (type Sb?) in Bo÷tes (RA 14 13 05.4, Dec +08 37 55)
Historical Identification: Per Dreyer, NGC 5511 (Hough (#6), 1860 RA 14 06 22, NPD 80 43.5) is "very faint, small, 10th magnitude star to west". The position precesses to RA 14 13 16.5, Dec +08 37 02, eight to ten seconds of time east of a pair of galaxies and close to an 11th magnitude star lying to their east (not west, as undoubtedly mis-stated by Hough). Presumably what Hough observed was one of the two galaxies, but which has become a matter of some controversy. The one listed above is smaller and fainter than the other one (PGC 50778), which is discussed immediately below; but the fainter galaxy has a much higher surface brightness and should be far easier for a visual observer to see than the much lower surface brightness galaxy. The note about Bigourdan's failure to observe NGC 5511 is meant to show that the galaxies were indeed very hard to see visually, in which case the higher surface brightness of PGC 50771 should make its identification as NGC 5511 virtually certain; but there are still places where its apparent companion is (presumably mis-)identified as NGC 5511.
Warning About Non-Standard Designations: NGC 5511 is sometimes called "NGC 5511B", and PGC 50778 is sometimes called "NGC 5511A". This is probably due to the occasional identification of PGC 50778 as NGC 5511; but it is also a good example of why non-standard letter designations should never be used. The correct approach is to call PGC 50771 "NGC 5511" without any additional lettering, and the other galaxy "PGC 50778" without any reference to an NGC entry.
Physical Information: Based on a recessional velocity of 7315 km/sec, a straightforward calculation indicates that NGC 5511 is about 340 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 330 million light years away at the time the light by which we see it was emitted, about 335 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.5 by 0.15 arcmin, the galaxy is about 45 to 50 thousand light years across.
SDSS image of region near spiral galaxy NGC 5511, also showing PGC 50778, the galaxy sometimes misidentified as NGC 5511
Above, a 12 arcmin wide SDSS image centered on NGC 5511, also showing PGC 50778
Below, a 0.6 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5511

PGC 50778 (= PGC 2807028 = "NGC 5511A")
Not an NGC object but listed here since sometimes misidentified as NGC 5511 or called NGC 5511A
A magnitude 14.0 spiral galaxy (type Sm? pec) in
Bo÷tes (RA 14 13 08.3, Dec +08 37 08)
Historical Identification: As noted in the entry for NGC 5511, PGC 50778 is sometimes (almost certainly incorrectly) identified as NGC 5511; however, its very low surface brightness makes it extremely unlikely that Hough could have seen it, and it would certainly have been far less noticeable than its higher surface-brightness northwestern companion, so it is almost certain that it does not belong in the NGC.
Note About PGC Designations: LEDA does not list PGC 50778 as also being PGC 2807028, but NED does; and although the position listed in LEDA for PGC 2807028 does not correspond to any specific object, its location on the southeastern rim of PGC 50778, its radial velocity and its description make it clear that the two PGC entries are for the same galaxy.
Physical Information: Based on a recessional velocity of 7375 km/sec, a straightforward calculation indicates that PGC 50778 is about 340 to 345 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 330 to 335 million light years away at the time the light by which we see it was emitted, about 335 to 340 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.7 by 0.7 arcmin, the galaxy is about 65 to 70 thousand light years across. PGC 50778 is at nearly the same distance as NGC 5511, so they may be close enough to be gravitationally interacting, in which case that interaction might explain the peculiar appearance of PGC 50778.
SDSS image of spiral galaxy PGC 50778, which is sometimes misidentified as NGC 5511
Above, a 1 arcmin wide SDSS image of PGC 50778; see NGC 5511 for a wider-field view

NGC 5512 (= PGC 50749)
Discovered (May 3, 1883) by
╔douard Stephan
A magnitude 14.2 elliptical galaxy (type E3?) in Bo÷tes (RA 14 12 41.1, Dec +30 51 18)
Historical Identification: Per Dreyer, NGC 5512 (Stephan list XIII (#71), 1860 RA 14 06 32, NPD 58 29.1) is "very faint, very small, round, suddenly brighter middle and nucleus, mottled but not resolved?". The position precesses to RA 14 12 41.6, Dec +30 51 25, just off the northeastern rim of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1885, but everything in the shorter papers is collected in A. N. 2661, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 4375 km/sec, NGC 5512 is about 200 to 205 million light years away. Given that and its apparent size of about 0.45 by 0.35 arcmin, it is about 25 to 30 thousand light years across.
SDSS image of region near elliptical galaxy NGC 5512
Above, a 12 arcmin wide SDSS image centered on NGC 5512
Below, a 0.6 arcmin wide SDSS image of the galaxy
SDSS image of elliptical galaxy NGC 5512

NGC 5513 (= PGC 50776)
Discovered (Apr 20, 1792) by
William Herschel
Also observed (Mar 29, 1832) by John Herschel
A magnitude 12.6 lenticular galaxy (type S0?) in Bo÷tes (RA 14 13 08.6, Dec +20 24 59)
Historical Identification: Per Dreyer, NGC 5513 (= GC 3809, JH 1759, WH II 877, 1860 RA 14 06 36, NPD 68 55.1) is "pretty bright, pretty large, irregularly round". The position precesses to RA 14 13 08.2, Dec +20 25 26, just above the northern outline of the galaxy listed above, the description fits and there is nothing comparably nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 4995 km/sec, NGC 5513 is about 230 to 235 million light years away. Given that and its apparent size of 1.9 by 0.9 arcmin, it is about 125 to 130 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5513
Above, a 12 arcmin wide SDSS image centered on NGC 5513
Below, a 2.4 arcmin wide SDSS image of the galaxy and its companions
SDSS image of lenticular galaxy NGC 5513 and its companions

NGC 5514 (= PGC 50809)
Discovered (Apr 26, 1865) by
Heinrich d'Arrest
A magnitude 13.3 spiral galaxy (type Sb? pec) in Bo÷tes (RA 14 13 38.7, Dec +07 39 37)
Historical Identification: Per Dreyer, NGC 5514 (= GC 5758, d'Arrest, 1860 RA 14 06 45, NPD 81 40.7) is "faint, pretty small, round, little brighter middle, 16th magnitude star to northeast". The position precesses to RA 14 13 41.2, Dec +07 39 53, about 0.7 arcmin east northeast of a pair of galaxies, the description fits and there is nothing else nearby, so the identification is certain. The only question is whether only the brighter member of the pair should be treated as NGC 5514, or both of them. Some references count only the brighter member (which is listed above), because the region bright enough for d'Arrest to see is far larger and brighter in PGC 50809 than in the fainter galaxy; while other references count the pair, since they are a strongly interacting system.
Physical Information: Since PGC 50809 and PGC 93124 are an interacting pair they must be at the same distance from us. Under the circumstances, the best indicator of their distance is their average recessional velocity, not their individual velocities of 7045 km/sec for PGC 50809 or 7515 km/sec for PGC 93124. Based on their average recessional velocity of 7280 km/sec, a straightforward calculation indicates that the pair is about 340 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the pair was about 330 million light years away at the time the light by which we see it was emitted, about 335 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.85 by 0.3 arcmin, the main part of PGC 50809 is about 80 thousand light years across, while the 3.8 by 1.6 arcmin apparent size of the pair of galaxies and their outer extensions corresponds to about 365 thousand light years. PGC 50809 is listed as a starburst galaxy, which is one reason it is so much brighter than its neighbor (the other is that the brightest portion of PGC 93124 is obscured by clouds of dust).
SDSS image of region centered on spiral galaxy NGC 5514 and its companion, PGC 93124
Above, a 12 arcmin wide SDSS image centered on NGC 5514 and PGC 93124
Below, a 4.4 by 3.6 arcmin wide SDSS image of the entire system
SDSS image of spiral galaxy PGC 50809, also called NGC 5514, and spiral galaxy PGC 93124, including their faint outer extensions
Below, a 1.4 arcmin wide SDSS image of the central portion of the pair
SDSS image of interacting spiral galaxies NGC 5514 and PGC 93124

PGC 93124 (= "NGC 5514A")
Not an NGC object but listed here since sometimes incorrectly called NGC 5514A
A magnitude 14.5 compact galaxy (type Sbc? pec) in
Bo÷tes (RA 14 13 39.3, Dec +07 39 33)
Historical Note: As discussed above (in the entry for NGC 5514, which see for images), PGC 93124 is sometimes treated as part of NGC 5514, and sometimes (since its bright regions are smaller and fainter than those of PGC 50809) it is treated only as a companion to the NGC object.
Physical Information: As discussed above, PGC 93124 and PGC 50809 must be about 330 million light years away. Given that and its apparent size of about 0.65 by 0.4 arcmin, the main part of PGC 93124 is about 60 to 65 thousand light years across, while the 3.8 by 1.6 arcmin apparent size of the pair of galaxies and their outer extensions corresponds to about 365 thousand light years.

NGC 5515 (= PGC 50750)
Discovered (May 16, 1787) by
William Herschel
Also observed (Apr 28, 1827) by John Herschel
A magnitude 12.9 spiral galaxy (type Sab?) in Bo÷tes (RA 14 12 38.1, Dec +39 18 37)
Historical Identification: Per Dreyer, NGC 5515 (= GC 3810, JH 1760, WH III 685, 1860 RA 14 06 51, NPD 50 01.9) is "very faint, small, very little extended". The position precesses to RA 14 12 38.2, Dec +39 18 38, practically dead center 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 7720 km/sec, a straightforward calculation indicates that NGC 5515 is about 360 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 345 to 350 million light years away at the time the light by which we see it was emitted, about 350 to 355 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.4 by 0.6 arcmin, the galaxy is about 140 to 145 thousand light years across. NGC 5515 is listed as a Seyfert galaxy (type Sy 1.9).
SDSS image of region near spiral galaxy NGC 5515
Above, a 12 arcmin wide SDSS image centered on NGC 5515
Below, a 1.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5515

NGC 5516 (= PGC 50960)
Discovered (Jul 1, 1834) by
John Herschel
A magnitude 12.0 lenticular galaxy (type E/S0?) in Centaurus (RA 14 15 54.7, Dec -48 06 53)
Historical Identification: Per Dreyer, NGC 5516 (= GC 3811, JH 3562, 1860 RA 14 06 55, NPD 137 27.5) is "pretty faint, small, round, pretty suddenly brighter middle, small (faint) double star to northeast". The position precesses to RA 14 15 57.2, Dec -48 06 48, on the eastern rim of the galaxy listed above, the description fits perfectly (including the double star to the northeast) and there is nothing comparable nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 4125 km/sec, NGC 5516 is about 190 to 195 million light years away, in fair agreement with redshift-independent distance estimates of 210 to 255 million light years. Given that and its apparent size of 3.4 by 2.3 arcmin, the galaxy is about 190 thousand light years across.
DSS image of region near lenticular galaxy NGC 5516
Above, a 12 arcmin wide DSS image centered on NGC 5516
Below, a 4 arcmin wide image of the galaxy (Image Credit & © Carnegie-Irvine Galaxy Survey; used by permission)
Carnegie-Irvine Galaxy Survey image of lenticular galaxy NGC 5516

NGC 5517 (= PGC 50758)
Discovered (Apr 20, 1882) by
╔douard Stephan
A magnitude 13.8 spiral galaxy (type Sab?) in Bo÷tes (RA 14 12 51.2, Dec +35 42 39)
Historical Identification: Per Dreyer, NGC 5517 (Stephan list XII (#63), 1860 RA 14 06 55, NPD 53 37.7) is "faint, extremely small, round, brighter middle and nucleus". The position precesses to RA 14 12 52.2, Dec +35 42 51, just northeast of the rim of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1883, but everything in the shorter papers is collected in A. N. 2502, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 8365 km/sec, a straightforward calculation indicates that NGC 5517 is about 390 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 375 to 380 million light years away at the time the light by which we see it was emitted, about 380 to 385 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.2 by 0.6 arcmin, the galaxy is about 130 thousand light years across.
SDSS image of region near spiral galaxy NGC 5517
Above, a 12 arcmin wide SDSS image centered on NGC 5517
Below, a 1.5 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5517

NGC 5518 (= PGC 50817)
Discovered (May 10, 1882) by
╔douard Stephan
A magnitude 14.0 lenticular galaxy (type E/S0?) in Bo÷tes (RA 14 13 47.7, Dec +20 50 54)
Historical Identification: Per Dreyer, NGC 5518 (Stephan list XII (#64), 1860 RA 14 07 17, NPD 68 29.7) is "faint, very small, round, gradually brighter middle". The position precesses to RA 14 13 48.2, Dec +20 50 55, well within the outline of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1883, but everything in the shorter papers is collected in A. N. 2502, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 4795 km/sec, NGC 5518 is about 220 to 225 million light years away. Given that and its apparent size of about 0.8 by 0.75 arcmin, it is about 50 to 55 thousand light years across. The closeup image below seems to show some dusty obscuration of the nucleus, in which case the type might be S0/a instead of E/S0.
SDSS image of region near lenticular galaxy NGC 5518
Above, a 12 arcmin wide SDSS image centered on NGC 5518
Below, a 1.2 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5518

NGC 5519 (= PGC 50865 and probably =
NGC 5570)
Probably observed (Jan 23, 1784) by William Herschel (and later listed as NGC 5570)
Discovered (Apr 26, 1865) by Heinrich d'Arrest (and later listed as NGC 5519)
Also observed (May 13, 1896) by Guillaume Bigourdan (while listed as NGC 5519)
A magnitude 13.1 spiral galaxy (type SAB(rs)ab? pec) in Bo÷tes (RA 14 14 20.9, Dec +07 30 57)
Historical Identification: Per Dreyer, NGC 5519 (= GC 5759, d'Arrest, 1860 RA 14 07 25, NPD 81 49.3) is "very faint, pretty large, 10th magnitude star to west". The position precesses to RA 14 14 21.3, Dec +07 31 21, on the northern rim of the galaxy listed above, the description fits (including the star to the west) and there is nothing else nearby, so the identification is certain.
Discovery Notes: The second IC lists a corrected NPD (per Bigourdan) of 81 55. The supposedly corrected position precesses to RA 14 14 21.5, Dec +07 25 39, but there is nothing there, so this is a (rare) case where one of Bigourdan's observations makes things worse instead of better. Obviously, he must have made some kind of mistake. His comparison star is listed as an 11th magnitude star at (1900) RA 14 09 12, Dec +07 58, which he measured as 53 seconds of time east and 16.5 arcmin south of BD+8 2828. His offsets for NGC 5519 average 11.3 seconds east and 38 arcsec north of that comparison star. BD+8 2828 lies at J2000 RA 14 13 16.9, Dec +07 47 04 and has practically zero proper motion, so its 1896 position must have been essentially the same, or about (1900) RA 14 08 19.7, Dec +08 15 11. This would place his comparison star at (1900) RA 14 09 12.7, Dec +07 58 41, which is nearly the same position given by Bigourdan for his comparison star, and precesses almost exactly to the current position of the 11th magnitude star about 10 seconds west and 40 arcsec south of NGC 5519. Since this is essentially the same as Bigourdan's offsets, his measurements were reasonably accurate, and he should have obtained a position nearly identical to that of the galaxy and d'Arrest's position, but must have either miscalculated or misprinted the NPD quoted in the IC2 by about 5 arcmin.
Physical Information: Based on a recessional velocity of 7455 km/sec, a straightforward calculation indicates that NGC 5519 is about 345 to 350 million light years away, in good agreement with redshift-independent distance estimates of 225 to 405 million light years. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 335 to 340 million light years away at the time the light by which we see it was emitted, about 340 to 345 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.5 by 0.85 arcmin, the galaxy is about 145 to 150 thousand light years across.
SDSS image of region near spiral galaxy NGC 5519
Above, a 12 arcmin wide SDSS image centered on NGC 5519
Below, a 2 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5519

NGC 5520 (= PGC 50728)
Discovered (May 15, 1787) by
William Herschel
Also observed (Jun 12, 1887) by Guillaume Bigourdan
A magnitude 12.4 spiral galaxy (type SABb?) in Bo÷tes (RA 14 12 22.8, Dec +50 20 54)
Historical Identification: Per Dreyer, NGC 5520 (= GC 3812, WH III 676, 1860 RA 14 07 50, NPD 38 59.5) is "faint, small, a little extended, stellar". The second IC lists a corrected RA (per Bigourdan) of 14 07 15. The corrected position precesses to RA 14 12 22.7, Dec +50 21 02, within the northern outline of 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 1875 km/sec, NGC 5520 is about 85 to 90 million light years away, in good agreement with redshift-independent distance estimates of 60 to 145 million light years. Given that and its apparent size of about 1.7 by 0.85 arcmin, it is about 40 to 45 thousand light years across.
SDSS image of region near spiral galaxy NGC 5520
Above, a 12 arcmin wide SDSS image centered on NGC 5520
Below, a 1.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5520

NGC 5521 (= PGC 50931)
Discovered (Apr 10, 1828) by
John Herschel
A magnitude 13.8 spiral galaxy (type Sbc?) in Virgo (RA 14 15 23.7, Dec +04 24 31)
Historical Identification: Per Dreyer, NGC 5521 (= GC 3813, JH 1761, 1860 RA 14 08 21, NPD 84 56.1) is "faint, small, round, brighter middle". The position precesses to RA 14 15 22.9, Dec +04 24 40, on the northwestern rim of 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 5780 km/sec, NGC 5521 is about 270 million light years away. Given that and its apparent size of about 0.65 by 0.5 arcmin, it is about 50 thousand light years across.
SDSS image of region near spiral galaxy NGC 5521
Above, a 12 arcmin wide SDSS image centered on NGC 5521
Below, a 0.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5521

NGC 5522 (= PGC 50889)
Discovered (Mar 19, 1787) by
William Herschel
Also observed (May 23, 1887) by Guillaume Bigourdan
A magnitude 13.5 spiral galaxy (type Sb?) in Bo÷tes (RA 14 14 50.4, Dec +15 08 49)
Historical Identification: Per Dreyer, NGC 5522 (= GC 3814, WH III 644, 1860 RA 14 08 24, NPD 74 14.0) is "very faint, very small, extended". The second IC lists a corrected RA (per Bigourdan) of 14 08 08. The corrected position precesses to RA 14 14 50.2, Dec +15 06 43, about 2 arcmin nearly due south of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: GC 3814 lists this as a double nebula, but that is not the case.
Physical Information: Based on a recessional velocity of 4575 km/sec, NGC 5522 is about 210 to 215 million light years away, in good agreement with redshift-independent distance estimates of 185 to 230 million light years. Given that and its apparent size of about 1.75 by 0.4 arcmin, it is about 105 to 110 thousand light years across.
SDSS image of region near spiral galaxy NGC 5522
Above, a 12 arcmin wide SDSS image centered on NGC 5522
Below, a 1.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5522

NGC 5523 (= PGC 50895)
Discovered (May 19, 1784) by
William Herschel
Also observed (May 22, 1830) by John Herschel
A magnitude 12.2 spiral galaxy (type SA(s)cd?) in Bo÷tes (RA 14 14 52.3, Dec +25 19 03)
Historical Identification: Per Dreyer, NGC 5523 (= GC 3818, JH 1762, WH III 134, 1860 RA 14 08 31, NPD 64 00.9) is "faint, pretty large, pretty much extended 90░, 10th magnitude star to northwest". The position precesses to RA 14 14 52.4, Dec +25 19 51, only about 0.8 arcmin north of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain. (Note: The position listed above is the one required to center the nucleus of the galaxy on the SDSS imaging site; but (per Corwin) many references use a position about a second of time to the west.)
Physical Information: Based on a recessional velocity of 1040 km/sec, NGC 5523 is about 45 to 50 million light years away, in fair agreement with redshift-independent distance estimates of 55 to 75 million light years. Given that and its apparent size of 4.0 by 0.9 arcmin, the galaxy is about 55 to 60 thousand light years across.
SDSS image of region near spiral galaxy NGC 5523
Above, a 12 arcmin wide SDSS image centered on NGC 5523
Below, a 4.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5523

WORKING HERE

NGC 5524 (not =
PGC 50868)
Recorded (Apr 19, 1855) by R. J. Mitchell
Also observed (May 31, 1886) by Guillaume Bigourdan
A pair of stars in Bo÷tes (RA 14 13 48.7, Dec +36 22 53)
(Historical identification a mess; see Corwin)
Historical Identification: Per Dreyer, NGC 5524 (=GC 3819, 3rd Lord Rosse, 1860 RA 14 08 47▒, NPD 52 57▒) is "very faint". The second IC lists a corrected RA (per Bigourdan) of 14 08 33.
Common Misidentifications: PGC 50868 is often misidentified as NGC 5524, but is actually NGC 5527. The current status of this entry as "WORKING HERE" reflects the need for a thorough discussion of why the misidentification was made (and still exists in many references), and the hopefully accurate current identification was determined.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by R. J. Mitchell, as shown above.
Physical Information:

NGC 5525 (= PGC 50946)
Discovered (May 3, 1883) by
╔douard Stephan
A magnitude 12.8 lenticular galaxy (type S0/a?) in Bo÷tes (RA 14 15 39.2, Dec +14 16 57)
Historical Identification: Per Dreyer, NGC 5525 (Stephan list XIII (#72), 1860 RA 14 08 56, NPD 75 03.9) is "pretty faint, pretty small, irregularly round, brighter middle". The position precesses to RA 14 15 39.7, Dec +14 16 54, right on the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1885 but everything in the shorter papers is collected in A. N. 2661, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 5555 km/sec, NGC 5525 is about 255 to 260 million light years away, in good agreement with redshift-independent distance estimates of 215 to 275 million light years. Given that and its apparent size of about 1.5 by 0.85 arcmin, it is about 110 to 115 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5525
Above, a 12 arcmin wide SDSS image centered on NGC 5525
Below, a 2 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5525

NGC 5526 (= PGC 50832 = PGC 2570954)
Discovered (Apr 17, 1789) by
William Herschel
Also observed (May 1, 1831) by John Herschel
A magnitude 13.4 spiral galaxy (type Sbc?) in Ursa Major (RA 14 13 53.7, Dec +57 46 17)
Historical Identification: Per Dreyer, NGC 5526 (= GC 3820, JH 1763, WH III 804 = WH III 835, 1860 RA 14 09 18, NPD 31 34.4) is "very faint, small, extended, mottled but not resolved". The position precesses to RA 14 13 45.1, Dec +57 46 19, only about 1.1 arcmin west of the galaxy listed above, the description fits and save for a fainter apparent companion there is nothing else nearby, so the identification of NGC 5526 with the brighter member of the pair is certain. The only question is whether the fainter galaxy (PGC 50803) should be included in the NGC listing. There is nothing in the Herschels' descriptions to justify that, and the apparently smaller galaxy's brighter regions (which is all the Herschels would have been able to see) are so much smaller than those of PGC 50832 that NGC 5526 is almost certainly only that galaxy; but some references include the fainter galaxy in the NGC entry, so it is discussed immediately below. (Note: Whether or not PGC 50803 is part of NGC 5526, it is not physically associated with its brighter companion, as it is more than five times further away.)
Discovery Notes: Per a note in the GC, JH equated WH III 804 with WH III 835 in a handwritten note in his copy of his father's work, supported by Caroline Herschel's reductions of all three of William Herschel's sweeps of the region.
Physical Information: Based on a recessional velocity of 2005 km/sec, NGC 5526 is about 90 to 95 million light years away, in good agreement with redshift-independent distance estimates of 80 to 135 million light years. Given that and its apparent size of about 2.1 by 0.3 arcmin, it is about 55 to 60 thousand light years across.
SDSS image of region near spiral galaxy NGC 5526, also showing its apparent companion, PGC 50803
Above, a 12 arcmin SDSS image centered on NGC 5526, also showing PGC 50803
Below, a 2 arcmin wide SDSS image of the apparent pair
SDSS image of spiral galaxy NGC 5526, also showing its apparent companion, PGC 50803

PGC 50803 (almost certainly not part of
NGC 5526)
Almost certainly not an NGC object but listed here since sometimes treated as part of NGC 5526
A magnitude 14.4 spiral galaxy (type SB(rs)bc?) in Ursa Major (RA 14 13 49.9, Dec +57 46 11)
Historical Identification: As discussed in the entry for NGC 5526, that designation almost certainly corresponds only to the much larger, brighter member of the apparent pair; but some references treat PGC 50803 as part of the NGC object. (Note: Whether or not PGC 50803 is part of NGC 5526, it is not physically associated with its brighter companion, as it is more than five times further away.)
Physical Information: Based on a recessional velocity of 11990 km/sec, a straightforward calculation indicates that PGC 50803 is about 560 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 530 to 535 million light years away at the time the light by which we see it was emitted, about 540 to 545 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.8 by 0.7 arcmin, the galaxy is about 125 thousand light years across.
SDSS image of spiral galaxy PGC 50803, also showing part of its apparent companion, NGC 5526
Above, a 1 arcmin wide SDSS image of PGC 50803, also showing part of NGC 5526 (which see)

WORKING HERE

NGC 5527 (= PGC 50868, and not =
NGC 5524 or PGC 50925)
Discovered (Apr 19, 1855) by R. J. Mitchell
A magnitude 13.8 spiral galaxy (type Sbc) in Bo÷tes (RA 14 14 27.2, Dec +36 24 16)
(Historical identification a mess; see Corwin)
Historical Identification: Per Dreyer, NGC 5527 (= GC 3821, 3rd Lord Rosse, 1860 RA 14 09 19▒, NPD 53 06▒) is "most extremely faint".
Common Misidentifications: PGC 50925 is often misidentified as NGC 5527, and PGC 50868 as NGC 5524. The current status of this entry as "WORKING HERE" reflects the need for a thorough discussion of why the misidentifications were made (and still exist in many references), and the hopefully accurate current identifications were determined.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by R. J. Mitchell, as shown above.
Physical Information: Apparent size 0.8 by 0.7 arcmin

PGC 50925 (not =
NGC 5527)
Not an NGC object but listed here since often misidentified as NGC 5527
More to follow ASAP; until then, see the wide-field image of NGC 5529

NGC 5528 (= PGC 50981)
Discovered (Mar 23, 1887) by
Lewis Swift
A magnitude 13.9 lenticular galaxy (type (R)SAB0(rs)a?) in Bo÷tes (RA 14 16 19.9, Dec +08 17 37)
Historical Identification: Per Dreyer, NGC 5528 (Swift list VI (#65), 1860 RA 14 09 31, NPD 81 03.1) is "most extremely faint, pretty small, round, 2 very faint stars near". The position precesses to RA 14 16 25.7, Dec +08 17 47, about 1.4 arcmin east northeast of 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 7335 km/sec, a straightforward calculation indicates that NGC 5528 is about 340 to 345 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 330 to 335 million light years away at the time the light by which we see it was emitted, about 335 to 340 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.5 by 0.7 arcmin, the galaxy is about 145 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5528
Above, a 12 arcmin wide SDSS image centered on NGC 5528
Below, a 1.8 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5528

NGC 5529 (= PGC 50942)
Discovered (May 1, 1785) by
William Herschel
Also observed (Mar 11, 1831) by John Herschel
A magnitude 11.9 spiral galaxy (type Sbc? pec?) in Bo÷tes (RA 14 15 34.2, Dec +36 13 38)
Historical Identification: Per Dreyer, NGC 5529 (= GC 3822, JH 1764, WH III 414, 1860 RA 14 09 40, NPD 53 07.6) is "considerably faint, pretty large, very much extended 110░, very gradually very much brighter middle". The position precesses to RA 14 15 34.5, Dec +36 13 15, only about 0.3 arcmin south of the nucleus of the galaxy listed above, the description is a perfect fit and there is nothing comparable nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 2875 km/sec, NGC 5529 is about 130 to 135 million light years away, in good agreement with redshift-independent distance estimates of 120 to 190 million light years. Given that and its apparent size of about 6.0 by 0.6 arcmin, it is about 230 to 235 thousand light years across.
SDSS image of region near spiral galaxy NGC 5529, also showing PGC 50925, which is sometimes misidentified as NGC 5527
Above, a 12 arcmin wide SDSS image centered on NGC 5529, also showing PGC 50925 and PGC 50952
Below, a 6.5 arcmin wide image of the galaxy and its apparent neighbors
(Credit & © Adam Block/Mount Lemmon SkyCenter/University of Arizona; used by permission)
Mount Lemmon SkyCenter image of spiral galaxy NGC 5529, also showing PGC 50925, which is sometimes misidentified as NGC 5527

NGC 5530 (= PGC 51106)
Discovered (Apr 7, 1837) by
John Herschel
A magnitude 11.3 spiral galaxy (type SAB(rs)bc?) in Lupus (RA 14 18 27.3, Dec -43 23 17)
Historical Identification: Per Dreyer, NGC 5530 (= GC 3823, JH 3563, 1860 RA 14 09 42, NPD 132 43.5) is "a remarkable object, very faint, pretty much extended, extremely suddenly very much brighter middle equivalent to 12th magnitude star". The position precesses to RA 14 18 28.8, Dec -43 22 30, on the northern rim of the galaxy listed above, the description fits (though the reason for the suddenly much brighter middle is that there is a star superimposed on the nucleus) and there is nothing else nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 1195 km/sec, NGC 5530 is about 55 million light years away, in good agreement with redshift-independent distance estimates of 35 to 55 million light years. Given that and its apparent size of about 4.9 by 2.3 arcmin, the galaxy is about 80 thousand light years across.
DSS image of region near spiral galaxy NGC 5530
Above, a 12 arcmin wide DSS image centered on NGC 5530
Below, a 5 arcmin wide image of the galaxy (Image Credit & © Carnegie-Irvine Galaxy Survey; used by permission)
Carnegie-Irvine Galaxy Survey of spiral galaxy NGC 5530

WORKING HERE

PGC 50952
Not an NGC object but listed here since discovered prior to the publication of the NGC
Discovered (Apr 19, 1855) by
R. J. Mitchell
A magnitude 15(?) spiral galaxy (type Sbc?) in Bo÷tes (RA 14 15 44.8, Dec +36 10 42)
Historical Identification: Per Mitchell's 1855 observation, PGC 50952 (1860 RA 14 09 50.3, NPD 53 10.2) is a "small, round, very faint nebula southeast of h1764", h1764 being NGC 5529. There is only one object that can possibly be the one thus described by Mitchell, so the identification of PGC 50952 with Mitchell's object is certain.
Discovery Notes: On the night of Mitchell's observation with the 3rd Lord Rosse's 72-inch Leviathan, he observed NGC 5524, 5527, 5529 and the galaxy described here, but though Dreyer included the first three in the NGC he failed to include the fourth. Corwin and Steve Gottlieb discovered the omission independently, and Corwin includes it is in his list of "notngc" objects as CGCG 191-071.
Physical Information: Based on a recessional velocity of 7450 km/sec, a straightforward calculation indicates that PGC 50952 is about 345 to 350 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was just over 335 million light years away at the time the light by which we see it was emitted, just over 340 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.55 by 0.4 arcmin, the galaxy is about 50 to 55 thousand light years across.
SDSS image of region near spiral galaxy PGC 50952, which though not an NGC object was discovered before the publication of the NGC, also showing NGC 5529 and PGC 50925
Above, a 12 arcmin wide SDSS image centered on PGC 50952, also showing NGC 5529 and PGC 50925
Below, a 0.75 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy PGC 50952, which though not an NGC object was discovered before the publication of the NGC

NGC 5531 (= PGC 50999)
Discovered (Feb 7, 1862) by
Heinrich d'Arrest
A magnitude 13.5 lenticular galaxy (type S0?) in Bo÷tes (RA 14 16 43.2, Dec +10 53 07)
Historical Identification: Per Dreyer, NGC 5531 (= GC 3824, d'Arrest, 1860 RA 14 09 53, NPD 78 28.0) is "faint, small, round, III 47 ten seconds of time to the east", (WH) III 47 being NGC 5532. The position precesses to RA 14 16 42.9, Dec +10 52 55, on the southwestern rim of the galaxy listed above, the description fits and there is nothing comparable nearby, so the identification is certain. However, though d'Arrest could not have seen it, the galaxy's fainter companion (PGC 4409321) is sometimes listed as part of the NGC entry, so it is discussed immediately below.
Physical Information: Based on a recessional velocity of 7765 km/sec, a straightforward calculation indicates that NGC 5531 is about 360 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 350 million light years away at the time the light by which we see it was emitted, about 355 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.8 by 0.75 arcmin, the galaxy is about 80 to 85 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5531, also showing NGC 5532
Above, a 12 arcmin wide SDSS image centered on NGC 5531, also showing NGC 5532
Below, a 1.2 arcmin wide SDSS image of the galaxy and PGC 4409321
SDSS image of lenticular galaxy NGC 5531, also showing its companion, PGC 4409321, which is sometimes misidentified as part of NGC 5531

PGC 4409321 (not part of
NGC 5531)
Not an NGC object but listed here since sometimes listed as part of NGC 5531
A magnitude 15.5(?) lenticular galaxy (type S0?) in Bo÷tes (RA 14 16 43.6, Dec +10 52 53)
Designation Note: Although too faint for d'Arrest to have seen, or even to have affected his perception of NGC 5531 (which see for images), PGC 4409321 is sometimes listed as part of that NGC entry. (Note: Although assigned the designation of PGC 4409321, a search of the LEDA database fails to find that entry. SDSSJ141643.57+105252.4 is the only designation that works for a search in either LEDA or NED.)
Physical Information: Based on a recessional velocity of 8060 km/sec, a straightforward calculation indicates that PGC 4409321 is about 375 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 360 to 365 million light years away at the time the light by which we see it was emitted, about 365 to 370 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.25 by 0.2 arcmin, the galaxy is about 25 thousand light years across.

NGC 5532 (= PGC 51006)
Discovered (Mar 15, 1784) by
William Herschel
Also observed (May 9, 1825) by John Herschel
A magnitude 11.9 lenticular galaxy (type S0?) in Bo÷tes (RA 14 16 52.9, Dec +10 48 27)
Historical Identification: Per Dreyer, NGC 5532 (= GC 3825, JH 1765, WH III 47, 1860 RA 14 10 03, NPD 78 32.2) is "very faint, very small, round, gradually brighter middle, mottled but not resolved". The position precesses to RA 14 16 53.0, Dec +10 48 44, well within the outline of the galaxy listed above, the description fits and there is nothing comparable nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 7405 km/sec, a straightforward calculation indicates that NGC 5532 is about 345 million light years away, in good agreement with widely varying redshift-independent distance estimates of 140 to 345 million light years. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 335 million light years away at the time the light by which we see it was emitted, about 340 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.6 by 1.6 arcmin, the galaxy is about 155 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5532, also showing NGC 5531
Above, a 12 arcmin wide SDSS image centered on NGC 5532, also showing NGC 5531
Below, a 2.2 arcmin wide SDSS image of NGC 5532 and PGC 214240
SDSS image of lenticular galaxy NGC 5532 and its apparent companion, PGC 214240

WORKING HERE

IC 990 (= PGC 50958)
Not an NGC object but listed here since actually discovered before the publication of the NGC
Probably discovered (Apr 27, 1878) by John Dreyer
Discovered (May 31, 1886) by Guillaume Bigourdan (184)
A magnitude 14.7 lenticular galaxy (type S0??) in Bo÷tes (RA 14 15 49.1, Dec +39 47 54)
Discovery Notes: Per Corwin, on the evening of April 27, 1878, Dreyer was using the 4th Lord Rosse's 72-inch Leviathan to observe NGC 5536 and 5541, and noticed "Another nebula 4 arcmin ▒ northeast of an 11th magnitude star seen at the same set, but where is not stated; clouds interrupted". Steve Gottlieb suggested that the 11th magnitude star is TYC 3035-996-1 = GSC 03035-00996 at RA 14 15 36.4, Dec +39 45 58. That star is magnitude 10.7, and about 3.1 arcmin southwest of IC 990, so Dreyer was probably the first to see the object. Given the lack of a proper position, he was reluctant to include it in his catalog, so it has no NGC designation, but given its probable observation by Dreyer, Corwin includes it in his list of notngc objects, and I have therefore included it here.
Physical Information: Given its own entry, see IC 990 for anything else.

PGC 214240 (= "NGC 5532B")
Not an NGC object but listed here since sometimes called NGC 5532B
A magnitude 14.8 lenticular galaxy (type S0/a?) in
Bo÷tes (RA 14 16 53.4, Dec +10 47 54)
Nonstandard Designation: The non-standard designation NGC 5532B is not recognized by most references, so PGC 214240 should be used for any search. The galaxy probably has no connection to NGC 5532 (which see for images) save for being in nearly the same direction, as it is probably the best part of 20 million light years closer than its apparent companion.
Physical Information: Based on a recessional velocity of 6900 km/sec, PGC 214240 is about 315 to 320 million light years away. Given that and its apparent size of about 0.4 by 0.1 arcmin, it is about 35 to 40 thousand light years across.

NGC 5533 (= PGC 50973)
Discovered (May 1, 1785) by
William Herschel
Also observed (May 9, 1826) by John Herschel
A magnitude 11.8 spiral galaxy (type SA(rs)ab?) in Bo÷tes (RA 14 16 07.7, Dec +35 20 38)
Historical Identification: Per Dreyer, NGC 5533 (= GC 3826, JH 1766, WH II 418, 1860 RA 14 10 10, NPD 53 59.9) is "pretty bright, round, very suddenly much brighter middle, 2 or 3 stars involved". The position precesses to RA 14 16 06.6, Dec +35 21 00, within the northwestern outline of 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 3865 km/sec, NGC 5533 is about 180 million light years away, in good agreement with redshift-independent distance estimates of 120 to 185 million light years. Given that and its apparent size of about 3.7 by 2.3 arcmin (counting its fainter outer regions), it is about 190 to 195 thousand light years across.
SDSS image of region near spiral galaxy NGC 5533
Above, a 12 arcmin wide SDSS image centered on NGC 5533
Below, a 4 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5533

NGC 5534 (= PGC 51055)
Discovered (Apr 29, 1881) by
Wilhelm Tempel
Also observed (May 17, 1881) by ╔douard Stephan
A magnitude 12.3 spiral galaxy (type (R)SAB(s)ab? pec) in Virgo (RA 14 17 40.3, Dec -07 25 03)
Historical Identification: Per Dreyer, NGC 5534 (Stephan list XII (#65), Tempel list V (#30), 1860 RA 14 10 17, NPD 96 46.0) is "pretty faint, star involved, 12th magnitude star to northwest". The position precesses to RA 14 17 40.1, Dec -07 25 00, right on the galaxy listed above, the description fits save for the direction of the star (which is not an unusual mistake, since directions are often reversed in one way or another depending on the orientation of the telescope) and there is nothing comparable nearby, so the identification is certain.
Discovery Notes: Stephan published several papers in 1883, but everything in the shorter papers is collected in A. N. 2502, so I have used the reference number from that paper.
Physical Information: Based on a recessional velocity of 2625 km/sec, NGC 5534 is about 120 to 125 million light years away, in fair agreement with a single redshift-independent distance estimate of 100 to 105 million years. Given that and its apparent size of about 1.45 by 1.25 arcmin, it is about 50 to 55 thousand light years across. NGC 5534 is listed as a starburst galaxy, its peculiar structure probably influenced by its fainter companion, PGC 51057, which is discussed immediately below.
DSS image of region near spiral galaxy NGC 5534, also showing irregular galaxy PGC 51057
Above, a 12 arcmin wide DSS image centered on NGC 5534, also showing PGC 51057
Below, a 1.8 arcmin wide DSS image of the apparent pair
DSS image of spiral galaxy NGC 5534 and irregular galaxy PGC 51057

PGC 51057
Not an NGC object but listed here since probably a satellite of
NGC 5534
A magnitude 13.5(?) irregular galaxy (type Irr?) in Virgo (RA 14 17 41.5, Dec -07 25 01)
Physical Information: Based on a recessional velocity of 2580 km/sec, PGC 51057 is about 120 million light years away. Given that and its apparent size of about 0.45 by 0.3 arcmin, it is about 15 thousand light years across. PGC 51057 is about the same distance as NGC 5534 (which see for images), and the NED states that it is a satellite galaxy projected onto its larger apparent companion (though the relatively low-quality images shown here do not make that relationship clear). If so, some kind of interaction between the two is probably responsible for their peculiar structures.

NGC 5535 (= PGC 97424)
Discovered (May 8, 1864) by
Albert Marth
A magnitude 15.0 elliptical galaxy (type E2?) in Bo÷tes (RA 14 17 31.3, Dec +08 12 30)
Historical Identification: Per Dreyer, NGC 5535 (= GC 5760, Marth 273, 1860 RA 14 10 38, NPD 81 09) is "extremely faint, small, irregularly round". The position precesses to RA 14 17 32.8, Dec +08 12 00, only about 0.6 arcmin southeast of the galaxy listed above, the description is reasonable and there is nothing comparable nearby save for NGC 5539, which is too large, too bright and too far away from Marth's position to be a likely candidate; so the identification is considered certain.
Physical Information: Based on a recessional velocity of 17060 km/sec, a straightforward calculation indicates that NGC 5535 is about 795 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 740 to 745 million light years away at the time the light by which we see it was emitted, about 765 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.75 by 0.6 arcmin, the galaxy is about 160 to 165 thousand light years across. NGC 5535 is listed as a radio jet galaxy.
SDSS image of region near elliptical galaxy NGC 5535, also showing NGC 5539
Above, a 12 arcmin wide SDSS image centered on NGC 5535, also showing NGC 5539
Below, a 1.2 arcmin wide SDSS image of the galaxy
SDSS image of elliptical galaxy NGC 5535

NGC 5536 (= PGC 50986)
Discovered (Apr 29, 1788) by
William Herschel
Also observed (May 13, 1828) by John Herschel
A magnitude 13.5 spiral galaxy (type SB(rs)ab?) in Bo÷tes (RA 14 16 23.9, Dec +39 30 08)
Historical Identification: Per Dreyer, NGC 5536 (= GC 3827, JH 1768, WH III 731, 1860 RA 14 10 40, NPD 49 51.6) is "considerably faint, very small, round, southwestern of 2", the other being NGC 5541. The position precesses to RA 14 16 24.5, Dec +39 29 21, about 0.8 arcmin nearly due south of 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 5850 km/sec, NGC 5536 is about 270 to 275 million light years away. Given that and its apparent size of about 1.3 by 1.3 arcmin, it is about 100 to 105 thousand light years across. Compared to most spiral galaxies, it is singularly devoid of star-forming regions save near its nucleus, so if not for its arms it might easily be mistaken for a lenticular galaxy.
SDSS image of region near spiral galaxy NGC 5536, also showing NGC 5541
Above, a 12 arcmin wide SDSS image centered on NGC 5536, also showing NGC 5541
Below, a 1.6 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5536

NGC 5537 (= PGC 51047)
Discovered (May 8, 1864) by
Albert Marth
A magnitude 14.3 spiral galaxy (type Sb? pec) in Virgo (RA 14 17 37.1, Dec +07 03 18)
Historical Identification: Per Dreyer, NGC 5537 (= GC 5761, Marth 274, 1860 RA 14 10 40, NGC 82 18) is "most extremely faint, small, a little extended". The position precesses to RA 14 17 36.9, Dec +07 03 01, on the southern rim of 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 8655 km/sec, a straightforward calculation indicates that NGC 5537 is about 400 to 405 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 390 million light years away at the time the light by which we see it was emitted, about 395 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.9 by 0.4 arcmin, the galaxy is about 100 to 105 thousand light years across.
SDSS image of region near spiral galaxy NGC 5537
Above, a 12 arcmin wide SDSS image centered on NGC 5537
Below, a 1 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5537

NGC 5538 (= PGC 51056)
Discovered (Mar 6, 1851) by
Bindon Stoney
Discovered (May 8, 1864) by Albert Marth
A magnitude 14.7 spiral galaxy (type Sab?) in Bo÷tes (RA 14 17 42.5, Dec +07 28 36)
Historical Identification: Per Dreyer, NGC 5538 (= GC 3830 = GC 5762, 3rd Lord Rosse, Marth 275, 1860 RA 14 10 41, NPD 81 53) is "extremely faint, small, extended". The position precesses to RA 14 17 37.1, Dec +07 28 01, almost 1.5 arcmin west southwest of the galaxy listed above, but the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by Bindon Stoney, as shown above. Also, in his 1877 Supplement to the GC he notes that this object is (per the Philosophical Transactions of 1861) about 10 arcmin southwest of h1770 (= NGC 5546), and states that (Heinrich) d'Arrest observed a nebula 4 seconds west and 5.4 arcmin north of h1770, which is NGC 5543.
Additional Note: For some reason Steinicke's latest database equates PGC 51056 with PGC 91351, but that is a much fainter galaxy several arcmin to the south of NGC 5538.
Physical Information: Based on a recessional velocity of 6905 km/sec, NGC 5538 is about 320 to 325 million light years away. Given that and its apparent size of about 0.85 by 0.2 arcmin, it is about 80 thousand light years across.
SDSS image of region near spiral galaxy NGC 5538, also showing NGC 5542 and PGC 91351
Above, a 12 arcmin wide SDSS image centered on NGC 5538, also showing NGC 5542 and PGC 91351
Below, a 1 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5538

PGC 91351
Not an NGC object but listed here due to its incorrect identification as
NGC 5538 (noted in that entry)
A magnitude 16.5(?) galaxy (type Sd?) in Bo÷tes (RA 14 17 45.3, Dec +07 25 26)
Physical Information: Based on a recessional velocity of 7005 km/sec, a straightforward calculation indicates that PGC 91351 is about 325 to 330 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was just over 315 million light years away at the time the light by which we see it was emitted, about 320 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.95 by 0.1 arcmin, the galaxy is about 85 to 90 thousand light years across.
SDSS image of region near spiral galaxy PGC 91351, also showing NGC 5538
Above, a 12 arcmin wide SDSS image centered on PGC 91351, also showing NGC 5538
Below, a 1.2 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy PGC 91351

NGC 5539 (= PGC 51054)
Discovered (Apr 24, 1830) by
John Herschel
A magnitude 13.7 lenticular galaxy (type S0?) in Bo÷tes (RA 14 17 37.8, Dec +08 10 47)
Historical Identification: Per Dreyer, NGC 5539 (= GC 3828, JH 1767, 1860 RA 14 10 44, NPD 81 10.2) is "faint, pretty large, irregular figure, gradually brighter middle". The position precesses to RA 14 17 38.8, Dec +08 10 49, on the eastern rim of the galaxy listed above, the description is reasonable and there is nothing comparable nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 17440 km/sec, a straightforward calculation indicates that NGC 5539 is about 810 to 815 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 760 million light years away at the time the light by which we see it was emitted, about 780 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.95 by 0.75 arcmin, the galaxy is about 210 thousand light years across.
SDSS image of region near lenticular galaxy NGC 5539, also showing NGC 5535
Above, a 12 arcmin wide SDSS image centered on NGC 5539, also showing NGC 5535
Below, a 1.4 arcmin wide SDSS image of the galaxy
SDSS image of lenticular galaxy NGC 5539

NGC 5540 (= PGC 50883)
Discovered (Apr 17, 1789) by
William Herschel
A magnitude 13.9 elliptical galaxy (type E2?) in Ursa Major (RA 14 14 54.4, Dec +60 00 40)
Historical Identification: Per Dreyer, NGC 5540 (= GC 3829, WH III 805, 1860 RA 14 10 45, NPD 29 20.1) is "extremely faint, very small, round, stellar". The position precesses to RA 14 14 55.4, Dec +60 00 46, well within the outline of the galaxy listed above, the description fits and there is nothing comparable nearby, so the identification is certain.
Physical Information: Based on a recessional velocity of 10980 km/sec, a straightforward calculation indicates that NGC 5540 is about 510 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 490 million light years away at the time the light by which we see it was emitted, about 500 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.8 by 0.6 arcmin, the galaxy is about 115 thousand light years across.
SDSS image of region near elliptical galaxy NGC 5540
Above, a 12 arcmin wide SDSS image centered on NGC 5540
Below, a 1.2 arcmin wide SDSS image of the galaxy
SDSS image of elliptical galaxy NGC 5540

NGC 5541 (= PGC 50991)
Discovered (Apr 29, 1788) by
William Herschel
Also observed (Apr 28, 1827) by John Herschel
A magnitude 12.7 spiral galaxy (type SAB(rs)bc? pec) in Bo÷tes (RA 14 16 31.8, Dec +39 35 21)
Historical Identification: Per Dreyer, NGC 5541 (= GC 3831, JH 1769, WH III 732, 1860 RA 14 10 48, NPD 49 45.7) is considerably faint, small, round, gradually brighter middle, northeastern of 2", the other being NGC 5536. The position precesses to RA 14 16 32.1, Dec +39 35 16, almost dead center on the galaxy listed above, the description is reasonable and there is nothing else nearby so the identification is certain.
Discovery Notes: NGC 5541 is part of a pair of interacting galaxies, and on some occasions both members of the pair are referred to as the NGC object. However, per Corwin, the Herschels couldn't have seen the much fainter eastern component (discussed immediately below as PGC 4540101), so only PGC 50991 should be listed as NGC 5541, and the other galaxy as merely an interacting companion.
Physical Information: Based on a recessional velocity of 7700 km/sec, a straightforward calculation indicates that NGC 5541 is about 355 to 360 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 345 to 350 million light years away at the time the light by which we see it was emitted, about 350 to 355 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.9 by 0.5 arcmin, the brighter portions of the galaxy are about 90 thousand light years across, while the apparent extent of its fainter outer regions of nearly 1.4 by 0.9 arcmin corresponds to about 140 thousand light years.
SDSS image of region near NGC 5541, also showing NGC 5536 and PGC 4540101
Above, a 12 arcmin wide SDSS image centered on NGC 5541, also showing NGC 5536 and PGC 4540101
Below, a 1.4 arcmin wide SDSS image of NGC 5536 and its apparent companion
SDSS image of region near NGC 5541, also showing PGC 4540101

"PGC 4540101"
Not an NGC object but listed here since an interacting companion of
NGC 5541
A magnitude 16.5(?) spiral galaxy (type SAB(rs)cd? pec) in Bo÷tes (RA 14 16 32.4, Dec +39 35 31)
Historical Misidentification: As noted in the entry for NGC 5541 (which see for images), PGC 4540101 is sometimes treated as part of that entry. However, per Corwin, it is too faint for the Herschels to have noticed, so its brighter companion is the only object that should be considered equivalent to NGC 5541. In looking at the images shown above, the reader must realize that in modern photographs faint galaxies look far more impressive than they do in visual observations; and aside from the four magnitude difference in brightness between the two galaxies, the obscuration of the nucleus of PGC 4540101 by clouds of dust would have made even its brightest regions far too faint for the discoverers of the NGC objects to notice.
Additional Note: Although listed in LEDA as PGC 4540101, a search of the database for that entry returns no value. Instead, it is searchable in LEDA as SDSSJ141632.58+393530.1, and in the NED as SDSS J141632.35+393530.7, the small differences in its position (actual, LEDA and NED) being insignificant in comparison to its size.
Physical Information: There appear to be no distance estimates or radial velocity measurements available for "PGC 4540101", but since it is interacting with NGC 5541, it must also be about 345 to 350 million light years away. Given that and its apparent size of about 0.35 by 0.2 arcmin, the brighter portions of the galaxy are about 35 thousand light years across, while the apparent extent of its fainter outer regions of about 0.6 by 0.25 arcmin corresponds to about 60 thousand light years.

NGC 5542 (= PGC 51066)
Discovered (Mar 6, 1851) by
Bindon Stoney
Also observed (Apr 20, 1865) by Heinrich d'Arrest
A magnitude 14.2 spiral galaxy (type Sa?) in Bo÷tes (RA 14 17 53.2, Dec +07 33 32)
Historical Identification: Per Dreyer, NGC 5542 (= GC 3832, 3rd Lord Rosse, d'Arrest, 1860 RA 14 10 57, NPD 81 47.1) is "very faint, very small". The position precesses to RA 14 17 52.9, Dec +07 33 57, just off the northern rim of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by Bindon Stoney, as shown above.
Physical Information: Based on a recessional velocity of 7790 km/sec, a straightforward calculation indicates that NGC 5542 is about 360 to 365 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 350 to 355 million light years away at the time the light by which we see it was emitted, about 355 to 360 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.65 by 0.35 arcmin, the galaxy is about 65 to 70 thousand light years across.
SDSS image of region near spiral galaxy NGC 5542, also showing NGC 5538, NGC 5543 and NGC 5546
Above, a 12 arcmin SDSS image centered on NGC 5542, also showing NGC 5538, 5543 and 5546
Below, a 1 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5542

NGC 5543 (= PGC 51079)
Discovered (Apr 26, 1865) by
Heinrich d'Arrest
A magnitude 14.6 spiral galaxy (type Sab?) in Bo÷tes (RA 14 18 04.1, Dec +07 39 18)
Historical Identification: Per Dreyer, NGC 5543 (= GC 5763, d'Arrest, 1860 RA 14 11 09, NPD 81 41.1) is "extremely faint, very small". The position precesses to RA 14 18 04.7, Dec +07 39 58, only about 0.6 arcmin nearly due north of 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 7090 km/sec, a straightforward calculation indicates that NGC 5543 is about 330 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 320 million light years away at the time the light by which we see it was emitted, about 325 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.5 by 0.2 arcmin, the galaxy is about 45 to 50 thousand light years across.
SDSS image of region near spiral galaxy NGC 5543, also showing NGC 5542 and NGC 5546
Above, a 12 arcmin SDSS image centered on NGC 5543, also showing NGC 5542 and 5546
Below, a 0.8 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 5543

NGC 5544 (= PGC 51018, and with
NGC 5545 = Arp 199)
Discovered (May 1, 1785) by William Herschel
Also observed (Apr 19, 1827) by John Herschel
A magnitude 13.0 lenticular galaxy (type (R)SB0(rs)a?) in Bo÷tes (RA 14 17 02.5, Dec +36 34 18)
Historical Identification: Per Dreyer, NGC 5544 (= GC 3833, JH 1771, WH II 419, 1860 RA 14 11 09, NPD 52 46.7) is "faint, pretty small, elongated 80░, and a double nebula (with NGC 5545) or binuclear". The position precesses to RA 14 17 01.7, Dec +36 34 19, well within the western outline of the western member of the double galaxy corresponding to the description, and save for its companion there is nothing else nearby, so the identification is certain.
Discovery Notes: Per Steinicke, John Herschel observed this object three times (in sweeps 69, 71 and 72, on Apr 19, 23 and 27, 1827). In the first two sweeps he described it as elongated, but in the third sweep he realized it was double. So Apr 19, 1827 is the correct date for his observing the brighter of the two galaxies involved (NGC 5544), while Apr 27, 1827 is the correct date for his discovering the fainter one (NGC 5545).
Physical Information: NGC 5544 has a recessional velocity of 3040 km/sec, but NGC 5545, which lies in front of it and is almost certainly interacting with it, has a recessional velocity of 3080 km/sec, indicating that their peculiar velocities (the difference in their recessional velocities due to an actual motion relative to each other) must be larger than the difference in their velocities due to the expansion of the Universe. Under the circumstances, the best measure of their distance is probably a Hubble distance based on the average of their individual radial velocities, which is 3060 km/sec. Based on that, the distance of the pair should be about 140 to 145 million light years, in good agreement with redshift-independent distance estimates of 125 to 150 million light years. Given that and its apparent size of about 1.2 by 1.2 arcmin, NGC 5544 is about 50 thousand light years across. NGC 5544 and 5545 are used by the Arp Atlas as an example of galaxies with material ejected from the nucleus, but although the pair are almost certainly companions, they do not represent such an object.
SDSS image of region near lenticular galaxy NGC 5544 and spiral galaxy NGC 5545, which comprise Arp 199
Above, a 12 arcmin wide SDSS image centered on NGC 5544 and 5545
Below, a 1.8 arcmin wide SDSS image of the galaxies
SDSS image of lenticular galaxy NGC 5544 and spiral galaxy NGC 5545, which comprise Arp 199
Below, another image of the same region
(Image Credit & © Adam Block/Mount Lemmon SkyCenter/University of Arizona; used by permission)
Mount Lemmon SkyCenter image of lenticular galaxy NGC 5544 and spiral galaxy NGC 5545, which comprise Arp 199

NGC 5545 (= PGC 51023, and with
NGC 5544 = Arp 199)
Discovered (Apr 27, 1827) by John Herschel
Discovered (Apr 10, 1852) by Bindon Stoney
A magnitude 15.0 spiral galaxy (type SA(s)bc?) in Bo÷tes (RA 14 17 05.2, Dec +36 34 31)
Historical Identification: Per Dreyer, NGC 5545 (= GC 3834, (JH 1771a), 3rd Lord Rosse, 1860 RA 14 11 10, NPD 52 47) is "extended, a little brighter middle, and a double nebula (with NGC 5544) or binuclear". The position precesses to RA 14 17 02.7, Dec +36 34 01, about 0.7 arcmin southwest of the galaxy listed above and actually within the southern outline of NGC 5544; but the pair fits the description and there is nothing else nearby, so per the NGC practice of assigning designations in order of right ascension, the identification of NGC 5545 as the eastern member of the pair is certain.
Discovery Notes: Dreyer's Introduction to the NGC states that many of the 3rd Lord Rosse's discoveries were actually made by one of his assistants, in this case by Bindon Stoney, as shown above.
Additional Discovery Notes: As stated in the discussion of NGC 5544, Herschel observed that object on three nights, but only realized he was looking at a double nebula on the third night (that is why his observation date for NGC 5544 is different from his discovery date for NGC 5545). However, neither the GC nor the NGC gave Herschel credit for the discovery of the second nebula, so many references list Lord Rosse or Bindon Stoney as the sole discoverer of NGC 5545.
Physical Information: As discussed in the entry for NGC 5544 (which see for the details), it and NGC 5545 are almost certainly interacting galaxies, and must be at about the same distance of about 140 to 145 million light years. Given that and its apparent size of about 1.2 by 0.35 arcmin, NGC 5545 is about 50 thousand light years across. The pair is used by the Arp Atlas as an example of galaxies with material ejected from the nucleus, but although they are almost certaining interacting companions, they do not represent such an object. As seen in the images posted at the entry for NGC 5544, NGC 5545 lies in front of NGC 5544. How far in front is unknown, but their radial velocities are so similar that they must be fairly close companions, and the unusual star-forming activity in NGC 5545 (particularly in the arm that lies directly in front of NGC 5544) suggests that they are gravitationally interacting, in which case they may be almost as close together as they appear in their images.

NGC 5546 (= PGC 51084)
Discovered (May 1, 1786) by
William Herschel
Also observed (May 11, 1828) by John Herschel
A magnitude 12.3 elliptical galaxy (type E2?) in Bo÷tes (RA 14 18 09.2, Dec +07 33 52)
Historical Identification: Per Dreyer, NGC 5546 (= GC 3835 = GC 3836, JH 1770, WH III 551, 1860 RA 14 11 14, NPD 81 46.9) is "pretty bright, considerably small, gradually brighter middle". The position precesses to RA 14 18 09.9, Dec +07 34 11, on the northern rim of the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: JH estimated the position of WH III 551 from his father's statement that it was about 3 or 4 arcmin west of WH III 552, and since objects observed in a given sweep could be considerably north or south of each other, although using the same NPD as for III 552, he added a ▒ sign to indicate the uncertainty in its north-south position. Many readers of the GC might presume that means a small uncertainty, rather than the possible uncertainty of 15 or more arcmin (in this case, about 12 arcmin), so it could appear that WH III 551 is much closer to WH III 552 than to JH 1770. But Dreyer's note in The Scientific Papers of Sir William Herschel states that III 551 and III 552 were observed in the same sweep (as suggested but not proven by being observed on the same date), so they must represent different objects, and III 551 must be NGC 5546.
Physical Information: Based on a recessional velocity of 7325 km/sec, a straightforward calculation indicates that NGC 5546 is about 340 million light years away, in good agreement with redshift-independent distance estimates of 330 to 345 million light years. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 330 million light years away at the time the light by which we see it was emitted, about 335 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.9 by 1.5 arcmin, the galaxy is about 180 to 185 thousand light years across.
SDSS image of region near elliptical galaxy NGC 5546, also showing NGC 5542 and NGC 5543
Above, a 12 arcmin wide SDSS image centered on NGC 5546, also showing NGC 5542 and 5543
Below, a 2.2 arcmin wide SDSS image of the galaxy
SDSS image of elliptical galaxy NGC 5546

NGC 5547 (= PGC 50543, and not =
IC 4404)
Discovered (Dec 20, 1797) by William Herschel
Also observed (Jul 24, 1887 and Apr 24, 1900) by Guillaume Bigourdan
A magnitude 13.9 spiral galaxy (type S? pec) in Ursa Minor (RA 14 09 45.3, Dec +78 36 04)
Historical Identification: Per Dreyer, NGC 5547 (= GC 3837, WH III 948, 1860 RA 14 11 36, NPD 10 44.8) is "extremely faint, very small, extended 0░▒". The position precesses to RA 14 10 09.6, Dec +78 35 51, about 1.2 arcmin east southeast of the galaxy listed above, the description is a reasonable fit and there is nothing comparable nearby, so the identification is certain.
Discovery Notes: NGC 5547 is misidentified in LEDA (and per Corwin, most likely in other places as well) as also being IC 4404. However, there is no doubt that IC 4404 is actually a star to the east of NGC 5547, as on the second night Bigourdan observed NGC 5547 he also observed IC 4404, and both nights he observed IC 4404 (Aug 22, 1884 and Apr 24, 1900) his positions point exactly at the star.
Physical Information: Based on a recessional velocity of 11700 km/sec, a straightforward calculation indicates that NGC 5547 is about 545 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 520 million light years away at the time the light by which we see it was emitted, about 530 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.6 by 0.4 arcmin, the galaxy is about 90 thousand light years across. The galaxy appears to be binuclear, so it may actually be two galaxies in collision, rather than a single object.
DSS image of region near peculiar spiral galaxy NGC 5547, also showing the star listed as IC 4404
Above, a 12 arcmin wide DSS image centered on NGC 5547, also showing IC 4404
Below, a 0.8 arcmin wide DSS image of the galaxy
DSS image of peculiar spiral galaxy NGC 5547

WORKING HERE

NGC 5548 (= PGC 51074)
Discovered (May 19, 1784) by
William Herschel
Also observed (May 22, 1830) by John Herschel
A magnitude 12.6 lenticular galaxy (type (R)SA0(s)a?) in Bo÷tes (RA 14 17 59.6, Dec +25 08 13)
Historical Identification: Per Dreyer, NGC 5548 (= GC 3838, JH 1773, WH II 194, 1860 RA 14 11 38, NGC 64 12.7) is "considerably faint, pretty small, round, very suddenly very much brighter middle resembling a star". The position precesses to RA 14 17 58.9, Dec +25 08 23, right on the galaxy listed above, the description fits and there is nothing else nearby, so the identification is certain.
Physical Information: Apparent size 1.5 by 1.2 arcmin?? 1.4 by 1.3 arcmin?? Vr 5150 km/sec, 92.5 to 341 Mpc, Sy 1.5, radio jet

NGC 5549 (= PGC 51118)
Discovered (May 1, 1786) by
William Herschel
Also observed (May 9, 1828) by John Herschel
A magnitude 12.9 lenticular galaxy (type S0) in Virgo (RA 14 18 38.8, Dec +07 22 39)
Historical Identification: Per Dreyer, NGC 5549 (= GC 3839, JH 1772, WH III 552, 1860 RA 14 11 43, NPD 81 58.7) is "very faint, very small, round". The position precesses to RA 14 18 39.2, Dec +07 22 26, on the southern rim of the galaxy listed above, and although the description might seem to better apply to a smaller object than shown in modern photographs, considering the limitations of visual observing it isn't at all inappropriate. In addition, there is no other suitable candidate nearby, so the identification is considered absolutely certain.
Physical Information: Based on a recessional velocity of ? km/sec, a straightforward calculation indicates that ? is about ? million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about ? million light years away at the time the light by which we see it was emitted, about ? million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about ? arcmin, the galaxy is about ? thousand light years across. Apparent size 2.0 by 0.8 arcmin??, 1.6 by 0.75 arcmin?? Vr 7705 km/sec, z 0.025701,
SDSS image of lenticular galaxy NGC 5549
Above, a 2.4 arcmin wide closeup of NGC 5549
Below, a 12 arcmin wide region centered on the galaxy
SDSS image of region near lenticular galaxy NGC 5549
Celestial Atlas
(NGC 5450 - 5499) ←     NGC Objects: NGC 5500 - 5549     → (NGC 5550 - 5599)