Celestial Atlas
(NGC 3900 - 3949) ←     NGC Objects: NGC 3950 - 3999 Link for sharing this page on Facebook     → (NGC 4000 - 4049)
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3950, 3951, 3952, 3953, 3954, 3955, 3956, 3957, 3958, 3959, 3960, 3961, 3962, 3963, 3964, 3965, 3966,
3967, 3968, 3969, 3970, 3971, 3972, 3973, 3974, 3975, 3976, 3977, 3978, 3979, 3980, 3981, 3982, 3983,
3984, 3985, 3986, 3987, 3988, 3989, 3990, 3991, 3992, 3993, 3994, 3995, 3996, 3997, 3998, 3999

Page last updated Jan 20, 2015
WORKING: Add positions/physical data (per Steinicke)

NGC 3950 (= PGC 37294)
Discovered (Apr 27, 1875) by
Lawrence Parsons, 4th Lord Rosse
A 16th-magnitude elliptical galaxy (type E1?) in Ursa Major (RA 11 53 41.1, Dec +47 53 06)
Based on a recessional velocity of 22365 km/sec, a straightforward calculation suggests that NGC 3950 is about 1.04 billion light years away. However, for objects at such a distance, we need to take the Universal expansion into account. Doing that shows that the galaxy was about 955 million light years away when the light by which we see it left the galaxy, about 990 million years ago (the difference between the two numbers being due to the expansion of the intervening space in that interval). Given that and its apparent size of 0.40 by 0.35 arcmin, the galaxy is about 110 thousand light years across.
SDSS image of NGC 3950
Above, a 2.4 arcmin wide closeup of NGC 3950 and the northern part of NGC 3949
Below, a 12 arcmin wide view centered on NGC 3949
SDSS image of region near NGC 3949 and 3950

NGC 3951
Discovered (Apr 10, 1785) by
William Herschel

NGC 3952 (=
IC 2972)
Discovered (Mar 11, 1787) by William Herschel (and later listed as NGC 3952)
Discovered (Mar 23, 1895) by Lewis Swift (and later listed as IC 2972)

NGC 3953 (= PGC 37306)
Discovered (Mar 12, 1781) by
Pierre Méchain
Discovered (Apr 12, 1789) by William Herschel
Also observed (Feb 17, 1831) by John Herschel
A magnitude 10.1 spiral galaxy (type SB(r)bc?) in Ursa Major (RA 11 53 48.4, Dec +52 19 30)
Historical Identification: Per Dreyer, NGC 3953 (= GC 2606 = JH 1011 = WH V 45, 1860 RA 11 46 29, NPD 36 53.1) is "considerably bright, large, extended 0°±, very suddenly bright middle and large mottled but not resolved nucleus". The position precesses to RA 11 53 49.8, Dec +52 20 11, on the northern rim of the nucleus of the galaxy listed above and well within its outline, the description fits and there is nothing else nearby, so the identification is certain.
Discovery Notes: Until 2006 it was thought that Méchain's observation was of what became NGC 3992 (which see for more information about Méchain's discovery), and neither the Herschels nor Dreyer were aware of the prior observation under any identification, causing the lack of any mention of the French astronomer in either NGC entry.
Physical Information: Based on a recessional velocity of 1050 km/sec, NGC 3953 is about 50 million light years away, in good agreement with redshift-independent distance estimates of 40 to 75 million light years. Given that and its apparent size of 6.6 by 3.1 arcmin, the galaxy is about 95 thousand light years across.
SDSS image of region near spiral galaxy NGC 3953
Above, a 12 arcmin wide SDSS image centered on NGC 3953

NGC 3954
Discovered (Apr 26, 1785) by
William Herschel

NGC 3955
Discovered (Dec 21, 1786) by
William Herschel

NGC 3956
Discovered (Mar 10, 1785) by
William Herschel

NGC 3957 (=
IC 2965)
Discovered (Feb 7, 1785) by William Herschel (and later listed as NGC 3957)
Discovered (Feb 20, 1898) by Lewis Swift (and later listed as IC 2965)

NGC 3958
Discovered (Mar 18, 1790) by
William Herschel

NGC 3959
Discovered (May 19, 1881) by
Wilhelm Tempel (V-11/12)

NGC 3960
Discovered (Apr 30, 1826) by
James Dunlop (349)

NGC 3961
Discovered (Apr 7, 1793) by
William Herschel

NGC 3962
Discovered (Feb 8, 1785) by
William Herschel

NGC 3963
Discovered (Mar 18, 1790) by
William Herschel

NGC 3964
Discovered (Mar 30, 1827) by
John Herschel

NGC 3965
Discovered (1886) by
Francis Leavenworth (II-452)

NGC 3966 (=
NGC 3986)
Discovered (Apr 29, 1827) by John Herschel (and later listed as NGC 3986)
Discovered (May 8, 1864) by Heinrich d'Arrest (and later listed as NGC 3966)
The second IC lists a corrected RA (per Wolf list VIII) of 11 48 29, and notes that d'Arrest made only one observation.

NGC 3967
Discovered (May 19, 1881) by
Wilhelm Tempel (V-13/14)

NGC 3968
Discovered (Apr 17, 1784) by
William Herschel

NGC 3969
Discovered (1886) by
Ormond Stone (II-453)
The second IC adds (per Howe) "RA 11 48 01, NPD 108 08.9, the star is 8.5 magnitude, and is nearly north".

NGC 3970
Discovered (Mar 9, 1828) by
John Herschel

NGC 3971 (=
NGC 3984)
Discovered (Feb 3, 1788) by William Herschel (and later listed as NGC 3971)
Discovered (Apr 10, 1831) by John Herschel (and later listed as NGC 3984)

NGC 3972
Discovered (Apr 14, 1789) by
William Herschel

NGC 3973
Discovered (Mar 15, 1855) by
R. J. Mitchell

NGC 3974
Discovered (Mar 9, 1828) by
John Herschel

NGC 3975
Discovered (Feb 21, 1874) by
Lawrence Parsons, 4th Lord Rosse

NGC 3976
Discovered (Apr 13, 1784) by
William Herschel

NGC 3977 (=
NGC 3980)
Discovered (Apr 14, 1789) by William Herschel (and later listed as NGC 3977)
Discovered (Apr 16, 1885) by Lewis Swift (and later listed as NGC 3980)

NGC 3978
Discovered (Mar 19, 1790) by
William Herschel

NGC 3979 (=
IC 2976)
Discovered (Apr 23, 1881) by Edward Holden (6) (and later listed as NGC 3979)
Discovered (May 23, 1897) by Lewis Swift (and later listed as IC 2976)

NGC 3980 (=
NGC 3977)
Discovered (Apr 14, 1789) by William Herschel (and later listed as NGC 3977)
Discovered (Apr 16, 1885) by Lewis Swift (1-18) (and later listed as NGC 3980)

NGC 3981
Discovered (Feb 7, 1785) by
William Herschel

NGC 3982
Discovered (Apr 14, 1789) by
William Herschel

NGC 3983
Discovered (Apr 10, 1785) by
William Herschel

NGC 3984 (=
NGC 3971)
Discovered (Feb 3, 1788) by William Herschel (and later listed as NGC 3971)
Discovered (Apr 10, 1831) by John Herschel (and later listed as NGC 3984)
The second IC says "3984: Nothing in this place, Wolf list VIII (h. one observation, about which he seemed rather doubtful)".

NGC 3985
Discovered (Feb 5, 1788) by
William Herschel

NGC 3986 (=
NGC 3966)
Discovered (Apr 29, 1827) by John Herschel (and later listed as NGC 3986)
Discovered (May 8, 1864) by Heinrich d'Arrest (and later listed as NGC 3966)

NGC 3987
Discovered (Apr 6, 1785) by
William Herschel

NGC 3988
Discovered (Apr 13, 1831) by
John Herschel

NGC 3989
Discovered (Apr 27, 1854) by
R. J. Mitchell

NGC 3990
Discovered (Apr 14, 1789) by
William Herschel

NGC 3991
Discovered (Feb 5, 1864) by
Heinrich d'Arrest

NGC 3992 (=
M109 = PGC 37617)
Supposedly but undoubtedly not discovered (Mar 12, 1781) by Pierre Méchain
Discovered (between late March and early May 1781) by Charles Messier but not added to his Catalog
Independently discovered (Apr 12, 1789) by William Herschel
Also observed (Feb 17, 1831) by John Herschel
Appended (1953) to Messier's Catalog by Owen Gingerich as M109
A magnitude 9.8 spiral galaxy (type SB(rs)bc?) in Ursa Major (RA 11 57 35.4, Dec +53 22 25)
Historical Identification: Per Dreyer, NGC 3992 (= GC 2635 = JH 1030 = WH IV 61, 1860 RA 11 50 19, NPD 35 51.3) is "considerably bright, very large, pretty much extended, suddenly brighter middle and bright mottled but not resolved nucleus". The position precesses to RA 11 57 36.0, Dec +53 21 57, barely south of the nucleus of the galaxy and well within its outline, there is nothing else nearby and the description fits, so the identification is certain.
Discovery Notes: Méchain's observation of Mar 12, 1781 was long thought to be the first observation of this object, but as of his letter of May 6, 1783 to Bernoulli he had still not determined its position, and in 2006 Henrik Bril found that based on the "Fortin Chart" Méchain used, he almost certainly observed NGC 3953, instead. Sometime soon after (in late March, April or early May of 1781) Messier observed both NGC 3953 and 3992, and recorded a handwritten position in his personal copy of his Catalog that has the right ascension of NGC 3953, but the declination of NGC 3992. That position is obviously not terribly good, but since its declination agrees with that of NGC 3992, it is reasonably certain that Messier did observe that galaxy, and on that basis Owen Gingerich added it to the Messier Catalog as M109 (at the time thinking that Méchain was the original discoverer, but since it was recorded by Messier, Gingerich would undoubtedly have added it to the Messier Catalog regardless of which of the French astronomers had first right of discovery). Since Messier did not add it to his published Catalog, neither the Herschels nor Dreyer were aware of its prior observation when compiling their various catalogs, causing the lack of any mention of Méchain or Messier in the NGC.
Physical Information: Based on a recessional velocity of 1050 km/sec, NGC 3992 is about 50 million light years away, in reasonable agreement with widely varying redshift-independent distance estimates of 35 to 115 million light years. Given that and its apparent size of 7.3 by 4.2 arcmin, it is about 100 thousand light years across.
SDSS image of region near spiral galaxy NGC 3992, also known as M109
Above, a 12 arcmin wide SDSS image centered on NGC 3992
Below, another image of of the galaxy (Image Credit AURA, NSF, NOAO)
NOAO image of spiral galaxy NGC 3992, also known as M109

NGC 3993
Discovered (Apr 6, 1785) by
William Herschel

NGC 3994
Discovered (Apr 6, 1864) by
Heinrich d'Arrest

NGC 3995
Discovered (Feb 5, 1864) by
Heinrich d'Arrest

NGC 3996
Discovered (Apr 23, 1832) by
John Herschel

NGC 3997
Discovered (Feb 19, 1827) by
John Herschel

NGC 3998 (= PGC 37642)
Discovered (Apr 14, 1789) by
William Herschel
An 11th-magnitude lenticular galaxy (type S0) in Ursa Major (RA 11 57 55.9, Dec +55 27 14)
Apparent size 2.7 by 2.3 arcmin. Used by the de Vaucouleurs Atlas of Galaxy Types as an example of galaxy type SA(r)0°.
SDSS image of lenticular galaxy NGC 3998
Above, a 3 arcmin wide closeup of NGC 3998
Below, a 12 arcmin wide region centered on the galaxy, also showing NGC 3990
SDSS image of region near lenticular galaxy NGC 3998, also showing lenticular galaxy NGC 3990

NGC 3999 (= PGC 37647)
Discovered (Apr 25, 1878) by
Lawrence Parsons, 4th Lord Rosse
A 15th-magnitude lenticular galaxy (type S0?) in Leo (RA 11 57 56.4, Dec +25 04 06)
Apparent size 0.5 by 0.3 arcmin.
SDSS image of lenticular galaxy NGC 3999
Above, a 2.4 arcmin wide closeup of NGC 3999
Below, a 12 arcmin wide region centered on the galaxy, also showing NGC 4000 and 4005
SDSS image of region near lenticular galaxy NGC 3999, also showing spiral galaxies NGC 4000 and 4005 (glare from 8th-magnitude HD 103913 to be reduced later)
Celestial Atlas
(NGC 3900 - 3949) ←     NGC Objects: NGC 3950 - 3999     → (NGC 4000 - 4049)