List of satellite galaxies in the Milky Way

This list contains all known satellite galaxies of the Milky Way , as well as the remains of former satellites . All of these galaxies also belong to the local group . Together they form the Milky Way Subgroup, a subgroup of the Local Group. The Milky Way is given for reference.

Proper name / designation	Distance (thousand light years)	Diameter (thousand light years)	Type	discovery	Alternative name (s)	annotation
Milky Way	-	100-120	SBbc	prehistoric	galaxy	-
Canis major dwarf	024 ± 3	020th	(dIrr)	2003	Canis Major Overdensity	Remnant
Dwarf sagittarius elliptical galaxy	078 ± 7	010	dE	1994	SayDEG	in dissolution
Ursa Major II	100 ± 15	001	dSph	2006	-	-
Segue 2	114 ± 1	-	dSph	2007	-	-
Coma Berenices dwarf	137 ± 5	000.5	dSph	2006	Coma Dwarf	-
Large Magellanic Cloud	165 ± 5	025th	Irr / SBm	prehistoric	GMW, LMC, ESO 56-115, PGC 17223	largest satellite galaxy in the Milky Way
Small Magellanic Cloud	195 ± 15	015th	Irr / SBm	prehistoric	KMW, SMC, NGC 292, PGC 3085	-
Bootes-I-dwarf	196 ± 9	002	dSph	2006	Boo I dSph	Galaxy with the lowest brightness
Bootes-II-dwarf	136 ± 26	000.5	dSph	2007	Boo II dSph
Bootes III dwarf	150	000.5	dSph	2009	Boo III dSph
Ursa minor dwarf	215 ± 10	002	dSph / dE4	1954	UGC 9749, DDO 199, A1508	-
Sculptor dwarf	258 ± 13	003	dSph / dE3	1937	ESO 351-30, E351-G30, PGC 3589, A0058	-
Draco dwarf	267 ± 20	002	dSph / dE0	1954	UGC 10822, DDO 208, A1719	-
Sextans dwarf	280 ± 13	003	dSph	1990	PGC 88608	-
Ursa Major I.	325	003	dSph	2005	UMa I dSph	-
Carina dwarf	329 ± 16	002	dSph / dE3	1977	NGC 2403, ESO 206-220, E206-G220, PCG 19441	-
Hercules dwarf	430	002	dSph	2007	-
Fornax dwarf	450 ± 26	005	dSph / dE2	1938	ESO 356-04, E356-G04, PCG 10093, A0237	contains 6 globular clusters
Pisces II	585	000.4	dSph	2010	-	-
Leo II	669 ± 39	003	dSph / dE0	1950	UGC 6253, DDO 93, Harrington-Wilson 2, Leo B	-
Leo IV	520 ± 49	001	dSph	2006	-	-
Leo V	570 ± 30	000.9	dSph	2007	-	-
Canes-Venatici-I	718 ± 82	006th	dSph	2006	CVn I dSph	-
Canes-Venatici-II	490 ± 49	001	dSph	2006	CVn II dSph
Leo I	815 ± 82	003	dSph / dE3	1950	UGC 5470, DDO 74, A1006, Harrington-Wilson 1, Regulus Dwarf	-
Phoenix dwarf	1450 ± 100	002	dIrr / dSph	1976	ESO 245-7, PCG 6830	-
Leo T	1500	-	dSph / dIrr	2006	-
Reticulum II	100	-	dSph	2015
Eridanus II	1190	1.8	dSph	2015
Horologium I.	330	-	dSph?	2015
Pictor I	370	-	dSph?	2015
Phoenix ii	270	-	dSph?	2015
Grus I	390	-	dSph	2015
Eridanus III	290	-	dSph?	2015
Tucana II	230	-	dSph	2015
Triangulum II	100	0.23	dSph	2015	Laevens 2
Hydra II	420	0.46	dSph	2015
Pegasus III	700	0.36	dSph	2015
Grus II	170	0.62	dSph	2015
Tucana III	80	0.29	dSph	2015
Columba I	590	0.68	dSph	2015
Tucana IV	160	0.82	dSph	2015
Reticulum III	300	0.42	dSph	2015
Tucana V	180	0.10	dSph	2015
Indus II	700	1.2	dSph?	2015
Cetus II	100	0.10	dSph?	2015
Horologium II	250	0.30	dSph	2015
Draco II	70	0.13	dSph	2015
Sagittarius II	220	0.26	dSph	2015
Crater II	390	7.2	dSph	2016		Very low brightness galaxy
Aquarius II	350	1.0	dSph	2016
Hydrus I	90	0.326	dSph	2018	-
Antlia 2	0430	010		2018		most diffuse of all galaxies discovered so far

Unsecured

Proper name / designation	Distance (thousand light years)	Diameter (thousand light years)	Type	discovery	Alternative name (s)	annotation
Complex H	108	30th	unknown	2003	-	Remnant or possibly simple high-speed cloud
Virgo overdensity	30th	?	(dSph)	2005	Virgo stream, Virgo dwarf	Remnant
Willman 1	147	<1	dSph / GC	2004	SDSS J1049 + 5103	Possibly globular clusters
Barnard's Galaxy	1600	6th	IB (s) m	1884	NGC 6822, IC 4895, DDO 209, PGC 63616, MCG -02-50-006, IRAS 19420-1450, HIPASS J1944-14	is similar in structure and composition to the Small Magellanic Cloud
Leo III	2250 ± 325	4th	dIrr (IBm?)	1940	Leo A, UGC5364, DDO 69, PGC 28868	-
Tucana dwarf	2870 ± 130	2	dSph	1990	PGC 69519	-
Segue 1	75 ± 7	-	dSph / GC	2007	-	Possibly globular clusters

Galaxy types

dIrr: Irregular dwarf galaxy (dwarf irregular galaxy)
dE: Elliptical dwarf galaxy (dwarf elliptical galaxy)
dSph: Spheroid dwarf galaxy (dwarf spheroidal galaxy)
SBm: Irregular bar spiral
Irr: Irregular Galaxy (irregular galaxy)
IBm: irregular bar galaxy (similar to SBm)
GC: globular clusters (globular clusters)

Remarks

↑ Not to be confused with the irregular Sagittarius dwarf galaxy (SagDIG)
↑ Not to be confused with the galaxy cluster of the same name
↑ ^a ^b ^c Martin, NF; De Jong, JTA; Rix, HW: A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites . In: The Astrophysical Journal . 684 (2): 1075, 2008. doi : 10.1086 / 590336 .
↑ Grillmair, CJ (2009). Four New Stellar Debris Streams in the Galactic Halo. In: The Astrophysical Journal . 693 (2): 1118-1127. arxiv : 0811.3965 , bibcode : 2009ApJ ... 693.1118G , doi: 10.1088 / 0004-637X / 693/2/1118 .

↑ Not to be confused with the irregular Sculptor Dwarf Galaxy (SDIG)

↑ Not to be confused with the clusters of galaxies (Abell 1377), the dwarf galaxy was until the discovery of Ursa Major II simply as Ursa Major dwarf known

^ Ilka Lehnen-Beyel (2007). New neighbors for the Milky Way. In: Image of Science . Wissenschaft.de (8 new dwarf galaxies, including Leo T)

↑ JTA de Jong et al. (2007). Numerical Color-Magnitude Diagram Analysis of SDSS Data and Application to the New Milky Way satellites. In: Astronomical Journal . 135: 1361-1383, 2008. arxiv : 0708.3758 [astro-ph], doi: 10.1088 / 0004-6256 / 135/4/1361 (CVn I, UMa II and Leo T)

↑ ^a ^b ^c ^d ^e ^f ^g ^h Sergey E. Koposov, Vasily Belokurov, Gabriel Torrealba, N. Wyn Evans: Beasts of the Southern Wild. Discovery of a large number of Ultra Faint satellites in the vicinity of the Magellanic Clouds . In: The Astrophysical Journal . 805, March 10, 2015, p. 130. doi : 10.1088 / 0004-637X / 805/2/130 .

↑ ^a ^b ^c ^d ^e ^f ^g DES Collaboration: Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data . In: The Astrophysical Journal . 807, March 10, 2015, p. 50. doi : 10.1088 / 0004-637X / 807/1/50 .

↑ D. Crnojević, DJ Sand, D. Zaritsky, K. Spekkens, B. Willman, JR Hargis: DEEP IMAGING OF ERIDANUS II AND ITS LONE STAR CLUSTER . In: The Astrophysical Journal Letters . 824, No. 1, July.

↑ Nicolas F. Martin: HYDRA II: A FAINT AND COMPACT MILKY WAY DWARF GALAXY FOUND IN THE SURVEY OF THE MAGELLANIC STELLAR HISTORY . In: The Astrophysical Journal Letters . 804, No. 1, April 23, 2015, p. L5. doi : 10.1088 / 2041-8205 / 804/1 / L5 .

↑ Dongwon Kim, Helmut Jerjen, Dougal Mackey, Gary S. Da Costa, Antonino P. Milone: A HERO'S DARK HORSE: DISCOVERY OF AN ULTRA-FAINT MILKY WAY SATELLITE IN PEGASUS . In: The Astrophysical Journal Letters . 804, No. 2, May 12, 2015, p. L44. arxiv : 1503.08268 . doi : 10.1088 / 2041-8205 / 804/2 / L44 .

↑ Dongwon Kim, Helmut Jerjen, Marla Geha, Anirudh Chiti, Antonino P. Milone, Dougal Mackey, Gary da Costa, Anna Frebel, Blair Conn: PORTRAIT OF A DARK HORSE: PHOTOMETRIC PROPERTIES AND KINEMATICS OF THE ULTRA-FAINT MILKY WAY SATELLITE PEGASUS III . In: The Astrophysical Journal . 833, No. 1, July.

↑ ^a ^b ^c ^d ^e ^f ^g ^h A. Drlica-Wagner: Eight ultra-faint galaxy candidates discovered in Year Two of the Dark Energy Survey . In: The Astrophysical Journal . 813, No. 2, November 4, 2015, p. 109. doi : 10.1088 / 0004-637X / 813/2/109 .

↑ Dongwon Kim, Helmut Jerjen: Horologium II: A second ultra-faint Milky Way satellite in the Horologium constellation . In: The Astrophysical Journal Letters . 808, No. 2, July 28, 2015, p. L39. doi : 10.1088 / 2041-8205 / 808/2 / L39 .

↑ ^a ^{b B.} PM Laevens, NF Martin, EJ Bernard, EF Schlafly, B. Sesar: SAGITTARIUS II, DRACO II AND LAEVENS 3: THREE NEW MILKY WAY SATELLITES DISCOVERED IN THE PAN-STARRS 1 3π SURVEY . In: The Astrophysical Journal . 813, No. 1, November 1, 2015. doi : 10.1088 / 0004-637X / 813/1/44 .

↑ G. Torrealba, SE Koposov, V. Belokurov & M. Irwin: The Feeble Giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater . In: Monthly Notices of the Royal Astronomical Society . April 13, 2016. doi : 10.1093 / mnras / stw733 .

↑ G. Torrealba, SE Koposov. V. Belokurov, M. Irwin, M. Collins, M. Spencer, R. Ibata, M. Matteo, A. Bonaca, P. Jethwa: At the survey limits: discovery of the Aquarius 2 dwarf galaxy in the VST ATLAS and the SDSS data . In: Monthly Notices of the Royal Astronomical Society . 463, No. 1, July, pp. 712-722.

↑ Sergey E. Koposov, Matthew G. Walker, Vasily Belokurov, Andrew R. Casey, Alex Geringer-Sameth, Dougal Mackey, Gary Da Costa, Denis Erkal, Prashin Jethwa, Mario Mateo, Edward W. Olszewski, John I. Bailey III : Snake in the Clouds: A new nearby dwarf galaxy in the Magellanic bridge . In: Cornell University Library . April 17, 2018. arxiv : 1804.06430v1 .

[1] Not to be confused with the irregular Sagittarius dwarf galaxy (SagDIG)

[2] Not to be confused with the galaxy cluster of the same name

[Martin2008-3] Martin, NF; De Jong, JTA; Rix, HW: A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites . In: The Astrophysical Journal . 684 (2): 1075, 2008. doi : 10.1086 / 590336 .

[Grillmair2009-4] Grillmair, CJ (2009). Four New Stellar Debris Streams in the Galactic Halo. In: The Astrophysical Journal . 693 (2): 1118-1127. arxiv : 0811.3965 , bibcode : 2009ApJ ... 693.1118G , doi: 10.1088 / 0004-637X / 693/2/1118 .

[5] Not to be confused with the irregular Sculptor Dwarf Galaxy (SDIG)

[6] Not to be confused with the clusters of galaxies (Abell 1377), the dwarf galaxy was until the discovery of Ursa Major II simply as Ursa Major dwarf known

[7] Ilka Lehnen-Beyel (2007). New neighbors for the Milky Way. In: Image of Science . Wissenschaft.de (8 new dwarf galaxies, including Leo T)

[8] JTA de Jong et al. (2007). Numerical Color-Magnitude Diagram Analysis of SDSS Data and Application to the New Milky Way satellites. In: Astronomical Journal . 135: 1361-1383, 2008. arxiv : 0708.3758 [astro-ph], doi: 10.1088 / 0004-6256 / 135/4/1361 (CVn I, UMa II and Leo T)

[Koposov2015-9] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Sergey E. Koposov, Vasily Belokurov, Gabriel Torrealba, N. Wyn Evans: Beasts of the Southern Wild. Discovery of a large number of Ultra Faint satellites in the vicinity of the Magellanic Clouds . In: The Astrophysical Journal . 805, March 10, 2015, p. 130. doi : 10.1088 / 0004-637X / 805/2/130 .

[Bechtol2015-10] ↑ ^a ^b ^c ^d ^e ^f ^g DES Collaboration: Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data . In: The Astrophysical Journal . 807, March 10, 2015, p. 50. doi : 10.1088 / 0004-637X / 807/1/50 .

[Crnojevic2016-11] D. Crnojević, DJ Sand, D. Zaritsky, K. Spekkens, B. Willman, JR Hargis: DEEP IMAGING OF ERIDANUS II AND ITS LONE STAR CLUSTER . In: The Astrophysical Journal Letters . 824, No. 1, July.

[Martin2015-12] Nicolas F. Martin: HYDRA II: A FAINT AND COMPACT MILKY WAY DWARF GALAXY FOUND IN THE SURVEY OF THE MAGELLANIC STELLAR HISTORY . In: The Astrophysical Journal Letters . 804, No. 1, April 23, 2015, p. L5. doi : 10.1088 / 2041-8205 / 804/1 / L5 .

[Dongwon2015-13] Dongwon Kim, Helmut Jerjen, Dougal Mackey, Gary S. Da Costa, Antonino P. Milone: A HERO'S DARK HORSE: DISCOVERY OF AN ULTRA-FAINT MILKY WAY SATELLITE IN PEGASUS . In: The Astrophysical Journal Letters . 804, No. 2, May 12, 2015, p. L44. arxiv : 1503.08268 . doi : 10.1088 / 2041-8205 / 804/2 / L44 .

[Dongwon2016-14] Dongwon Kim, Helmut Jerjen, Marla Geha, Anirudh Chiti, Antonino P. Milone, Dougal Mackey, Gary da Costa, Anna Frebel, Blair Conn: PORTRAIT OF A DARK HORSE: PHOTOMETRIC PROPERTIES AND KINEMATICS OF THE ULTRA-FAINT MILKY WAY SATELLITE PEGASUS III . In: The Astrophysical Journal . 833, No. 1, July.

[Drlica-Wagner2015-15] ↑ ^a ^b ^c ^d ^e ^f ^g ^h A. Drlica-Wagner: Eight ultra-faint galaxy candidates discovered in Year Two of the Dark Energy Survey . In: The Astrophysical Journal . 813, No. 2, November 4, 2015, p. 109. doi : 10.1088 / 0004-637X / 813/2/109 .

[Kim2015-16] Dongwon Kim, Helmut Jerjen: Horologium II: A second ultra-faint Milky Way satellite in the Horologium constellation . In: The Astrophysical Journal Letters . 808, No. 2, July 28, 2015, p. L39. doi : 10.1088 / 2041-8205 / 808/2 / L39 .

[Laevens2015-17] {b B.} PM Laevens, NF Martin, EJ Bernard, EF Schlafly, B. Sesar: SAGITTARIUS II, DRACO II AND LAEVENS 3: THREE NEW MILKY WAY SATELLITES DISCOVERED IN THE PAN-STARRS 1 3π SURVEY . In: The Astrophysical Journal . 813, No. 1, November 1, 2015. doi : 10.1088 / 0004-637X / 813/1/44 .

[Torrealba2016-18] G. Torrealba, SE Koposov, V. Belokurov & M. Irwin: The Feeble Giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater . In: Monthly Notices of the Royal Astronomical Society . April 13, 2016. doi : 10.1093 / mnras / stw733 .

[TorrealbaAquarius2016-19] G. Torrealba, SE Koposov. V. Belokurov, M. Irwin, M. Collins, M. Spencer, R. Ibata, M. Matteo, A. Bonaca, P. Jethwa: At the survey limits: discovery of the Aquarius 2 dwarf galaxy in the VST ATLAS and the SDSS data . In: Monthly Notices of the Royal Astronomical Society . 463, No. 1, July, pp. 712-722.

[Koposov2018-20] Sergey E. Koposov, Matthew G. Walker, Vasily Belokurov, Andrew R. Casey, Alex Geringer-Sameth, Dougal Mackey, Gary Da Costa, Denis Erkal, Prashin Jethwa, Mario Mateo, Edward W. Olszewski, John I. Bailey III : Snake in the Clouds: A new nearby dwarf galaxy in the Magellanic bridge . In: Cornell University Library . April 17, 2018. arxiv : 1804.06430v1 .