List of smallest known stars

From Wikipedia, the free encyclopedia

This is a list of the smallest known stars, brown dwarfs and stellar remnants, sorted by increasing size. The list is divided into sublists, and contain notable objects up to 350,000 km in radius, or 0.50 R_☉, as well as all red dwarfs smaller than 0.1 R_☉ and all neutron stars with accurately measured radii.

0 to 1,000 km

Partial list containing stars up to 0.0014 R_☉.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star class	Notes	References
SGR J1935+2154	4.35+1.95 −1.35	Magnetar	Has one potential planet.	^[1]
RX J0720.4−3125	4.50+0.08 −0.09 – 5.38+0.13 −0.14	Neutron star		^[2]
Hercules X-1	8.10±0.41	Pulsar		^[3]
LMC X-4	8.301±0.2			^[3]
Centaurus X-3	9.178±0.130			^[3]
Vela X-1	9.56±0.0			^[3]
HESS J1731-347	10.40+0.86 −0.78	Neutron star	Lightest neutron star ever discovered, at a mass of 0.77 M_☉.^[4]^[5]	^[4]
PSR J0348+0432 A	11–15	Pulsar	Has a white dwarf companion.	^[6]
PSR J0437−4715	>11.1		Most stable known natural clock.	^[7]
GW170817 A	11.9±0.4			^[3]
GW170817 B	11.9±0.4			^[3]
PSR J1906+0746	11.99–12.85			^[8]
PSR J0205+6449	12	Pulsar	Pulsar located in the supernova remnant 3C 58.	^[9]
RX J1856.5−3754	12.1+1.3 −1.6	Neutron star	Nearest known neutron star.	^[7]
PSR J2043+1711	12.13–12.96	Pulsar		^[8]
PSR J1933-6211	12.15–12.98			^[8]
PSR J0952–0607 A	12.245+0.685 −0.315		Most massive neutron star so far discovered.	^[10]
4U 1702−429	12.4±0.4	Neutron star		^[11]
Vela pulsar	12.52–13.30	Pulsar		^[8]
PSR J1614−2230	13±2			^[3]
PSR J0348+0432	13±2			^[3]
PSR J0740+6620	13.7+2.6 −1.5			^[12]
ZTF J1406+1422 A	14	Neutron star	Has a substellar companion orbiting it closely.	^[13]
PSR J1748−2446Ad	16	Pulsar	Fasted spinning neutron star, it is constrained to a small size to avoid being torn apart, located in the star cluster Terzan 5, and potentially the largest known pulsar.	^[14]

1,000 to 50,000 km

Partial list containing stars from 0.0014 to 0.0718 R_☉.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star radius, R_☉	Star class	Notes	References
ZTF J1901+1458	2,140	0.003076+0.000230 −0.000331	White dwarf	The most massive white dwarf so far discovered, around 1.3 times more massive than the Sun, close to the mass limit of any white dwarf (the Chandrasekhar limit),^[15] and is also a candidate white dwarf pulsar.^[16]	^[15]
RE J0317-853	2,200	0.0032		Also among the most massive white dwarfs.	^[17]
SDSS J023836.27+764219.0	2,230	0.00321+0.00040 −0.00036		An ultramassive white dwarf ejected from the Hyades. At a mass of 1.317 `M`_☉, it is possibly the most massive known white dwarf consistent with single-star evolution.^[a]	^[18]^[19]^[20]
T Coronae Borealis	3,130	0.0045		Expected to become a nova in the near future, its apparent magnitude may increase up to 2.0.^[21]	^[22]
Janus	3,400	0.004887^+0.0010 _−0.00086		A white dwarf with a side of hydrogen and another side of helium.	^[23]
Wolf 1130 B	3,500	0.005		Nearest candidate for a supernova, a type Ia supernova.^[24]	^[24]
HD 49798 B	3,580	0.00515			^[25]
BPM 37093	4,060	0.00583±0.00008			^[26]
IK Pegasi B	4,200	0.006			^[27]
U Geminorum A	4,410	0.00634±0.00016			^[28]
WD 2317+1830	5,517	0.00793±0.00021			^[29]
BW Sculptoris	5,570	0.00800+0.00014 −0.00011			^[28]
Sirius B	5,634	0.008098±0.000046		Nearest white dwarf	^[30]
GRW +70 8247 (Gliese 742)	5,960	0.0086			^[31]^[b]
Gamma Cassiopeiae Ab	6,000	0.00862^+0.00009 _−0.00046			^[32]
AN Ursae Majoris	6,300	0.0091			^[33]
Gliese 915	6,750	0.0097±0.0001			^[34]
LP 658-2	6,778	0.0097			^[35]
BZ Ursae Majoris A	6,880	0.00989			^[36]
QS Virginis A	6,960	0.010±0.001			^[37]
AE Aquarii A	7,000	0.01		First discovered white dwarf pulsar.	^[38]
AR Scorpii A	7,000	0.01		A white dwarf pulsar. It is often mistaken as the first discovered white dwarf pulsar.	^[39]
YZ Leonis Minoris	7,000	0.01			^[40]
GW Librae	7,170	0.0103+0.0015 −0.0010			^[28]
WZ Sagittae	7,300	0.0105±0.0013			^[28]
MY Apodis	7,650	0.011±0.001			^[41]
OY Carinae A	7,650	0.011			^[42]
TMTS J0526+5934 A	7,650	0.011			^[43]
G 99-47	7,650	0.011			^[35]
EX Hydrae	7,650	0.011			^[44]
RX Andromedae	7,790	0.0112+0.0012 −0.0008			^[28]
van Maanen 2	7,860	0.01129 ± 0.00066		Third-closest white dwarf.	^[45]
Stein 2051 B	7,930	0.0114±0.0004			^[46]
G 107-70 B	8,224	0.0118			^[35]
Ross 548 (ZZ Ceti)	8,209	0.0118±0.0002			^[47]
39 Ceti B (AY Ceti B)	8,350	0.012			^[48]
WD 1054−226	8,350	0.012±0.001			^[49]
Gliese 440	8,550	0.0123 ± 0.0009		Fourth-closest white dwarf.	^[45]
Procyon B	8,585	0.01234±0.00032		Second-closest white dwarf.	^[50]
GD 165 A	8,627	0.0124±0.0003			^[35]
Epsilon² Arae C	8,627	0.0124±0.0003			^[34]
WD 0806−661 (Maru)	8,860	0.0127		Has one confirmed exoplanet.	^[35]
SW Ursae Majoris	8,975	0.0129+0.0009 −0.0010			^[28]
Epsilon Reticuli B	8,975–9,809	0.0129–0.0141			^[51]
G 29-38	8,975	0.0129			^[45]
AM Herculis A	9,040	0.013+0.0017 −0.0014			^[28]
40 Eridani B	9,100	0.01308±0.0002		First white dwarf to be discovered and the fifth-closest one.	^[52]
TY Coronae Borealis	9,110	0.0131±0.0014			^[34]
HD 147513 B	9,144	0.0131			^[45]
GD 358 (V777 Herculis)	9,170	0.0132			^[53]
Wolf 489	9,170	0.0132			^[35]
GALEX J2339−0424	9,253	0.0133±0.0008			^[54]
G 107-70 A	9,412	0.0135			^[35]
Wolf 1346	9,670	0.0139±0.0006			^[34]
WD 1032+011 A	10,230	0.0147±0.0013			^[55]
Gliese 318	10,300	0.0148			^[45]
RR Caeli A	10,909	0.01568±0.00009			^[56]
HL Tau 76	11,270	0.0162			^[57]
Mira B (VZ Ceti)	14,100	0.20		Based on the most likely mass estimate, 0.24±0.04 M_☉. Alternatively, it may have a mass of 0.42±0.02 M_☉ with a radius of 0.015 R_☉ (10,700 km).^[58]	^[58]
PG 1159-035	16,140 or 17,670	0.0232 or 0.0254±0.005	PG 1159 star (Pre-degenerate)	PG 1159 stars are pre-white dwarfs.	^[59]
WD 2226−210	17,390	0.025±0.001	White dwarf	Located in Helix Nebula	^[60]
WD 0032−317 A	18,510	0.0266±0.0012			^[61]
Feige 55	19,460	0.027965			^[62]^[c]
ZTF J1406+1422 B	20,200	0.029	Brown dwarf	A highly-irradiated brown dwarf with an orbital period of 62 minutes and a dayside surface temperature of 10,462 K,^[13] comparable to A-type stars such as Vega and Sirius.	^[13]
V906 Carinae A	20,900	0.03	White dwarf		^[63]
BE Ursae Majoris A	32,000	0.046±0.002	Subdwarf O star	Smallest known non-compact star.	^[64]
KPD 0005+5106	41,000	0.059+0.031 −0.018	Pre-white dwarf	Has one unconfirmed exoplanet.	^[65]
AG Pegasi B	41,700	0.06	White dwarf	In a symbiotic binary with AG Peg A, has undergone many mass transfer events, varying in radius, luminosity and temperature.	^[66]
Regulus Ab	42,440	0.061±0.011	Pre-white dwarf		^[67]
PSR J0348+0432 B	45,220	0.065±0.005	White dwarf	Orbiting a pulsar.	^[68]
TMTS J0526+5934 B	45,990	0.0661±0.0054	Subdwarf B star		^[43]
WISEA 1810−1010	46,610	0.067+0.032 −0.02	Brown dwarf		^[69]

50,000 to 125,000 km

Partial list containing stars from 0.0718 to 0.18 R_☉.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star radius, R_☉	Star class	Notes	References
SCR 1845−6357 B	50,000	0.0719±0.01	Brown dwarf		^[70]
SDSS 1624+00	52,200	0.075±0.001			^[71]
UGPS J0521+3640	52,900	0.076+0.004 −0.005			^[72]
DENIS 0255−4700	53,986	0.0776±0.0060		Faintest brown dwarf with a measured visual magnitude.	^[73]
SDSS J1007+1930	54,500	~0.078		Potential member of the Regulus system, which could be one of the most widely separated stellar systems. This brown dwarf is at 12.6 light-years from Regulus.	^[74]^[d]
WD 0032−317 B	54,890	0.0789+0.0085 −0.0083		A highly irradiated brown dwarf with a dayside temperature hotter than the surface of Sun. Its dayside temperature measures 7,900 K (7,630 °C), while its nightside is much cooler, at 1,970 K (1,700 °C).	^[61]
2MASS 1507−1627	55,700	0.08			^[75]
Epsilon Indi Ba	55,700	0.08–0.081			^[76]
WISE J0623-0456	55,800 or 79,400	0.0802+0.0175 −0.0134^[77] or 0.1141±0.0144^[78]
LHS 6343 C	56,340	0.08098±0.00442			^[79]
HD 19467 B	56,500	0.0812+0.0012 −0.0013			^[80]
WISE 1534–1043	56,500	0.0812+0.0072 −0.0062		This object has a very fast and unusual transverse velocity, and is believed to be very old and metal-poor to explain such unusual velocity.	^[81]
Epsilon Indi Bb	57,050	0.082–0.083			^[76]
Wolf 1130 C	57,200	0.0822±0.0021			^[82]
WISE 0458+6434 A	57,700	0.0829+0.0008 −0.0007			^[83]
WISE 0458+6434 B	57,700	0.0829+0.0008 −0.0007			^[83]
54 Piscium B	57,900	0.0832±0.0021			^[77]
Gliese 229 Ba	57,910	0.08324+0.00514 −0.01233			^[84]
CWISEP J1446−2317	58,620	0.084±0.002			^[71]
EBLM J0555−57Ab	58,720	0.0844+0.0131 −0.006	Red dwarf	Smallest known red dwarf.	^[85]
Scholz's Star B	58,770	0.08447+0.0015 −0.0016	Brown dwarf	A nearby star that passed through the Solar System's Oort cloud 80,000 years ago.	^[86]
EPIC 201702477b [fr]	59,340	0.0853±0.0041			^[87]
2MASS J0415−0935	60,460	0.0869±0.0005			^[80]
GJ 1245 C	60,530	0.087±0.004	Red dwarf		^[88]
Gliese 229 Bb	60,770	0.0874+0.0123 −0.0051	Brown dwarf		^[84]
SSSPM J0829-1309	61,220	0.088±0.003	Red dwarf	An L2 dwarf that is fusing hydrogen. SSSPM J0829−1309 is one of the least luminous and massive hydrogen-fusing stars, and is smaller than Jupiter.	^[89]^[90]
HD 63754 B	61,500–67,900	0.0884–0.0976	Brown dwarf	Among the most massive brown dwarfs.	^[91]
HD 72946 B	61,500	0.0884			^[92]
2MASS J09393548−2448279 B	63,000	0.09			^[93]
CWISEP J1047+5457	62,900	0.090+0.002 −0.001			^[71]
WISE J2354+0240	62,900	0.090+0.002 −0.001			^[71]
WISEPA J031325.96+780744.2	62,900	0.090±0.002			^[71]
Gliese 570 D	63,629	0.09146+0.0051 −0.0041			^[77]
2MASS 0243−2453	64,004–73,744	0.092–0.106			^[94]
ZTF J1239+8347 B	64,300–100,000	0.092–0.144		Within a brown dwarf binary system with an orbital period of 57.41 minutes, a separation close enough for it to lose mass to the primary via an accretion disk.	^[95]
2MASS J0348−6022	64,700	0.093+0.016 −0.010			^[96]
WISE 0146+4234 A	65,270	0.0938+0.0024 −0.0026			^[97]
Kelu-1 B	65,400 to 72,500	0.094 to 0.104			^[98]^[e]
SCR 1845−6357 A	65,470	0.0941±0.0039	Red dwarf		^[73]
WISE 0146+4234 B	65,670	0.09944+0.0035 −0.0015	Brown dwarf		^[97]
SDSS J1416+1348 A	65,700	0.0945±0.0082			^[99]
Kelu-1 A	66,000 to 74,900	0.095 to 0.108			^[98]^[f]
47 Ophiuchi C	66,500	0.0956±0.001			^[78]
WISE 1405+5534	66,500	0.0956±0.0010			^[71]
2MASS 0937+2931	67,200	0.0966±0.0164			^[100]
2MASS J1047+21	67,200	0.0966±0.0164			^[100]
CoRoT-15b	67,200	0.0966±0.0123			^[87]
SDSS J1416+1348 B	67,200	0.0966±0.0164			^[99]
WISE 0359−5401	67,200	0.0966±0.0021			^[101]
WISE 0734−7157	67,200	0.0966±0.0021			^[71]
WISE 2220−3628	67,200	0.0966±0.0014			^[102]
TVLM 513-46546	67,480—75,830	0.097–0.109		Has one confirmed exoplanet.	^[103]
CWISEP J1935-1546	67,900	0.0976±0.0143			^[104]
Eta Coronae Borealis C	67,900	0.0976±0.0031			^[78]
WISE 2150−7520 B	67,900	0.0976±0.0164			^[105]
LHS 1070 C	68,180	0.098		Certainly a brown dwarf based on its mass.^[106]	^[107]
WASP-30B	68,670	0.0987±0.0031			^[87]
WASP-128B	68,670	0.0987±0.0021			^[87]
Gliese 758 B	69,300	0.0997+0.0051 −0.0082			^[108]
HD 33632 Ab	69,350	0.0997			^[109]
2MASS J0407+1546	69,570	0.100+0.024 −0.008			^[96]
2MASS J1219+3128	69,570	0.100+0.027 −0.013			^[96]
HD 114762 B	69,570	0.100	Red dwarf		^[110]
R Aquarii B	>70,000	>0.1	White dwarf	Makes a symbiotic binary with its companion R Aquarii A, a red giant.	^[111]
EBLM J0954−23	70,266	0.101±0.017	Red dwarf		^[85]
KOI-189 B	70,474–71,796	0.1013–0.1032			^[112]
Scholz's Star A	70,900	0.1019+0.0006 −0.0007		A nearby star that passed through the Solar System's Oort cloud 80,000 years ago.	^[86]
Gliese 569 Bb	70,960	0.102±0.020	Brown dwarf	First brown dwarf ever discovered, together with its companion Gliese 569 Ba, which were thought to be a single astronomical body at the time.	^[113]
Luhman 16 A	70,960	0.102±0.005		Nearest brown dwarfs to Earth.	^[114]
Luhman 16 B	70,960	0.102±0.005		Nearest brown dwarfs to Earth.	^[114]
HD 28736 B	71,280	0.1025±0.0024			^[115]
15 Sagittae B	71,492	0.1028±0.0411			^[116]
GD 165 B	71,492	0.1028±0.008			^[100]
2MASS 0036+1821	72,210	0.1038±0.0072			^[117]
2MASS J11145133−2618235	72,210	0.1038±0.0113			^[72]
LHS 1070 B	72,350	0.104		Likely a brown dwarf based on its mass.^[106]	^[107]
WD 1032+011 B	73,190	0.1052±0.01		A brown dwarf orbiting a white dwarf with an extremely low orbital period of 0.09 days (2.2 hours), both being tidally locked to each other.^[55]	^[55]
WISE 2150-7520 A	73,640	0.1058±0.0062			^[105]
BW Sculptoris B	73,640	0.1058±0.0051		^[118]
Ross 614 B	74,100	~0.107	Red dwarf		^[119]
LHS 2924	74,440	0.107	Red dwarf	Was the smallest known star at its discovery.	^[120]
WISE 0855−0714	74,690	0.1074 ± 0.0074	Brown dwarf	Coolest-known brown dwarf, at 276 K (3 °C; 37 °F).^[121]	^[121]^[g]
DENIS J1048−3956	75,140	0.108	Red dwarf		^[122]
VZ Piscium B	75,800	0.1089±0.0041	Red dwarf	Also called NLTT 56936 B^[123] or HIP 115819 B.^[124]	^[78]
WISE 0607+2429	75,800	0.1089±0.0175	Brown dwarf		^[78]
WISE J2209+2711	75,800	0.1089±0.0010			^[71]
ESO 207-61	76,500	0.11±0.02		One of the first brown dwarfs to be identified.^[125]	^[78]
Kepler-39b	76,500	0.11±0.0031		Kepler-39 rotates rapidly with a rotation period of 1.6 hours and hence has an oblate shape, with its equator length being 22% larger than the poles.^[126]	^[87]
WISE J1206+8401	76,500	0.110±0.002			^[71]
CoRoT-3b	77,220	0.111±0.0051			^[87]
TOI-2119 B	77,220	0.111±0.0031			^[127]
2MASS 1237+6526	77,930	0.112±0.016		Has one unconfirmed exoplanet.	^[78]
WISE J1122+25	77,930	0.112±0.016			^[78]
LHS 2065	78,610	0.113±0.006	Red dwarf		^[128]
WISE 0825+2805	79,310	0.114±0.002	Brown dwarf		^[71]
WISE J004945.61+215120.0	80,100	0.1151±0.0123	Brown dwarf		^[78]
2MASS J0523−1403	80,500	0.1157±0.0065	Red dwarf		^[73]
KELT-1B	80,770	0.1161±0.0031	Brown dwarf		^[87]
LHS 292	80,980	0.1164±0.0044	Red dwarf	Not to be confused with LHS 2924 (see above)	^[73]
WISE 1541−2250	81,470	0.117±0.002	Brown dwarf		^[71]
vB 10	82,300	0.1183+0.0059 −0.0057	Red dwarf		^[128]
2M1540	82,790	0.119			^[129]^[h]
EI Cancri B	82,790	0.119±0.021			^[130]
Gliese 569 Ba	82,790	0.119±0.020	Brown dwarf	First brown dwarf ever discovered, together with its companion Gliese 569 Bb, which were thought to be a single astronomical body at the time.	^[113]
TRAPPIST-1	82,927	0.1192±0.0013	Red dwarf	Hosts a planetary system with seven confirmed planets.	^[131]
OGLE-TR-122B	83,480	0.120+0.024 −0.013		Was the smallest known star from 2005 to 2013.	^[132]
Teegarden's Star	83,480	0.120±0.012		Has three confirmed exoplanets.	^[133]
G 196-3 B	84,400	0.1213±0.00719	Brown dwarf		^[78]
Königstuhl 1 B	84,400	0.1213±0.0021	Brown dwarf		^[78]
vB 8	84,458	0.1214+0.006 −0.0057	Red dwarf		^[128]
LS IV-14 116	84,900	0.122	Subdwarf B star		^[134]
SPECULOOS-3	85,600	0.123±0.0022	Red dwarf	Has one confirmed exoplanet.	^[135]
ZTF J1239+8347 A	85,800	0.123+0.015 −0.011	Brown dwarf	Within a brown dwarf binary system with an orbital period of 57.41 minutes, a separation close enough for it to accrete mass from the secondary via an accretion disk.	^[95]
2MASS 0122-2439 B	85,800	0.123±0.021	Brown dwarf		^[136]
DX Cancri	85,920	0.1235±0.0006	Red dwarf		^[73]
2MASS J09393548−2448279 A	87,200	0.125+0.010 −0.009	Brown dwarf		^[137]
VHS J1256–1257b	87,200	0.125	Brown dwarf		^[138]
LHS 2090	86,960	0.125±0.005	Red dwarf		^[73]
LHS 288	87,380	0.1256±0.0042			^[73]
Gliese 412 B	87,797	0.1262±0.0054			^[139]
OY Carinae B	88,350	0.127			^[140]
AZ Cancri	88,630	0.1274±0.0195			^[78]
AS Leonis Minoris B	90,400 – 355,000	0.13–0.51	White dwarf or Subdwarf B star	AS Leonis Minoris is an eclipsing binary system made up of a luminous red giant (45–170 R_☉) and a hot companion (AS LMi B). It has the longest period of any known eclipsing binary at 69 years.	^[141]
GJ 1245 B	90,400	0.13±0.007	Red dwarf		^[142]
Gliese 623 B	92,350	0.133 ± 0.008			^[143]^[i]
Gliese 105 C	92,459	0.1329+0.0057 −0.0055			^[144]
Teide 1	93,711	0.1347+0.0123 −0.0077	Brown dwarf	First brown dwarf to be confirmed.	^[145]
CWISE J0506+0738	94,337	0.1356±0.0031	Brown dwarf		^[146]
EI Cancri A	94,620	0.136±0.020	Red dwarf		^[130]
Alpha Trianguli B	97,400	0.14			^[147]
LHS 1070 A	97,400	0.14			^[107]
HD 149382	99,485	0.143	Subdwarf B star		^[148]
EZ Aquarii A (Luyten 789-6 A)	99,485	0.143±0.022	Red dwarf		^[142]
EZ Aquarii B (Luyten 789-6 B)	99,485	0.143±0.022			^[142]
Wolf 359	100,180	0.144±0.004		Fifth-nearest star system to Earth.	^[128]
DENIS-P J1058.7−1548	101,500	0.1459±0.001	Brown dwarf		^[78]
GJ 1245 A	101,570	0.146±0.007	Red dwarf		^[88]
LP 944-20	102,900	0.1479±0.0144	Brown dwarf	Among the brightest brown dwarfs.	^[78]
Wolf 424 A	104,350	0.150±0.019	Red dwarf		^[130]
NY Virginis A	105,000	0.151±0.001	Subdwarf B star		^[149]
EX Hydrae B	105,300	0.1513	Red dwarf		^[44]
GJ 1061	105,750	0.152±0.007		Has three confirmed exoplanets.	^[128]
Wolf 424 B	106,440	0.153±0.019			^[130]
2MASS J1115+1937	107,240	0.154±0.010	Brown dwarf		^[150]
Proxima Centauri	107,280	0.1542±0.0045	Red dwarf	The nearest extrasolar star. Has one confirmed planet, one candidate, and one disputed	^[151]
85 Pegasi Bb	107,830	0.155	Red dwarf		^[152]
2M1510 A	109,400	0.157±0.003	Brown dwarf	The system has a candidate planet (2M1510 b) that orbits on a polar orbit, although it may be a false positive detection.	^[153]
2M1510 B	109,400	0.157±0.003			^[153]
WISE 0535−7500	109,380	0.157±0.004		May be a binary system of two smaller brown dwarfs.^[121]	^[71]
2MASS J0249−0557 c	110,620	0.159±0.003			^[154]
Gliese 65 B (Luyten 726-8 B)	110,620	0.159±0.006	Red dwarf	The Gliese 65 system may host a Neptune-mass planet.	^[155]
LP 40-365	111,000	0.16±0.01	White dwarf	A white dwarf that might have formed in a type Iax supernova.	^[156]
HD 53143 B	111,310	0.160±0.005	Red dwarf		^[157]
NY Virginis B	111,310	0.16			^[158]
GL Virginis	111,520	0.1603±0.0053			^[159]
TZ Arietis (GJ 9066)	112,010	0.161±0.014		Has one confirmed exoplanet.	^[142]
Gliese 65 A (Luyten 726-8 A)	114,790	0.165±0.006		The Gliese 65 system may host a Neptune-mass planet.	^[155]
Kepler-451 B	116,880	0.168±0.001			^[160]
YZ Ceti	116,880	0.168±0.009		Has three confirmed exoplanets.	^[161]
G 192-15	118,000	0.17±0.005		Has two confirmed exoplanets.	^[162]
HR 858 B	118,000	0.17±0.04			^[163]
LP 791-18	118,000	0.17±0.018		Has three confirmed exoplanets.	^[164]
UY Sextantis	118,000	0.17±0.01	Subdwarf B star		^[165]
Z Andromedae B	118,000 to 250,000	0.17±0.03 to 0.36±0.06	White dwarf	Makes a symbiotic binary with its companion Z Andromedae A, a red giant.	^[166]
HIP 81208 Cb	122,100	0.175 ± 0.009	Brown dwarf		^[167]
AB Doradus C	124,000	0.178	Red dwarf	Among the least massive stars confirmed.	^[168]^[j]
Gliese 22 B	124,530	0.179±0.009	Red dwarf		^[88]

125,000 to 200,000 km

Partial list containing stars from 0.18 to 0.287 R_☉.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star radius, R_☉	Star class	Notes	References
Groombridge 34 B (Gliese 15 B)	125,230	0.18±0.03	Red dwarf		^[169]
HW Virginis A	127,310	0.183±0.026	Subdwarf B star		^[170]
HU Delphini A	128,010	0.184±0.004	Red dwarf		^[142]
Gliese 29 B	129,400	0.186±0.014			^[157]
GJ 3323	129,540	0.1862±0.0059		Has two confrirmed exoplanets.	^[159]
Barnard's Star	130,100	0.187±0.001		Second-nearest star system to the Solar System. The star with the highest proper motion. Has three confirmed exoplanets.	^[128]
Alpha Mensae B	132,180	0.19±0.01			^[171]
GJ 1128	132,000	0.190±0.014			^[142]
Ross 248 (HH Andromedae)	132,180	0.19			^[139]
Ross 128 (Gliese 447)	137,750	0.198±0.007		Has one confirmed exoplanet.	^[128]
Ross 154 (V1216 Sagittarii)	139,140	0.200±0.008			^[128]
GJ 1062	140,500	0.202±0.012	Red subdwarf	Another size estimates include 0.372±0.076 R_☉^[172] and 0.411±0.051 R_☉.^[173]	^[174]
Kepler-70	141,200	0.203±0.007	Subdwarf B star	Has two unconfirmed exoplanets.	^[175]
Kepler-451 A	141,200	0.203±0.001	Subdwarf B star	Possibly has two exoplanets.	^[160]
RR Caeli B	141,200—149,600	(0.203–0.215) ± 0.015	Red dwarf		^[176]
GJ 1214 (Orkaria)	141,920	0.204+0.0085 −0.0084		Has one confirmed exoplanet.	^[128]
LHS 1140	142,600	0.205±0.008		Has two confirmed exoplanets.	^[128]
Krüger 60 B	145,400	0.209±0.017			^[130]
Ross 508	147,000	0.2113±0.0063		Has one confirmed exoplanet.	^[177]
GJ 1132	149,580	0.215±0.009			^[128]
QY Aurigae A	151,660	0.218±0.021			^[142]
QY Aurigae B	151,660	0.218±0.021			^[142]
Kepler-16 B	157,388	0.22623±0.00059		Has one confirmed exoplanet.	^[178]
Fomalhaut C	160,000	0.23 ± 0.01			^[179]^[k]
V391 Pegasi	160,000	0.23	Subdwarf B star	Has one unconfirmed exoplanet.	^[180]
Kepler-1658 C	160,000	0.23	Red dwarf		^[181]
Gliese 777 B	160,710	0.231±0.025	Red dwarf		^[142]
Kepler-1649	161,190	0.2317±0.0049	Red dwarf	Has two confirmed exoplanets.	^[182]
Eta Telescopii B	163,000	0.234±0.003	Brown dwarf		^[183]
Ross 47	165,580	0.238±0.009	Red dwarf		^[128]
Kepler-429	166,970	0.24	Subdwarf B star	Has three unconfirmed exoplanets.	^[184]
V906 Carinae B	166,970	0.24	Red dwarf or Orange dwarf		^[63]
CM Draconis B	171,000	0.2458±0.0010	Red dwarf		^[185]
2M1207 A	172,000	0.247+0.041 −0.082	Brown dwarf		^[186]
PZ Telescopii B	173,900	0.25+0.03 −0.04	Brown dwarf		^[187]
DG Canum Venaticorum A	176,010	0.253	Red dwarf		^[172]
Ross 614 A	176,710	0.254±0.028			^[172]
Gliese 625	177,400	0.255±0.034			^[188]
Gliese 12	182,060	0.2617+0.0058 −0.0070		Has one confirmed exoplanet.	^[189]
CM Draconis A	183,530	0.2638±0.0011			^[185]
HIP 79098 B	185,800	0.2672±0.0617	Brown dwarf		^[136]
BX Trianguli B	188,000	0.27±0.01	Red dwarf	Has one confirmed exoplanet.	^[190]
V846 Arae B	188,000	0.27±0.04	Subdwarf O star		^[191]
Mu Herculis C	189,930	0.273±0.032	Red dwarf		^[142]
40 Eridani C	190,620	0.274±0.011			^[139]
Struve 2398 B	194,800	0.280±0.005			^[192]
Gliese 643	194,800	0.280±0.028			^[193]
Gliese 402	197,580	0.284±0.011			^[128]
GJ 3991 A	197,580	0.286±0.011			^[128]
Epsilon Scorpii B	200,360	0.288±0.019		^[157]

200,000 to 275,000 km

Partial list containing stars from 0.29 to 0.395 solar radii.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star radius, R_☉	Star class	Notes	References
Gliese 105 B	201,060	0.289+0.012 −0.011	Red dwarf		^[144]
CoRoT-7 B	201,800	0.29			^[194]
Mu Cassiopeiae Ab	201,800	0.29			^[195]
AP Columbae	202,400	0.291±0.009		The nearest pre-main sequence star to Earth.	^[157]
Kapteyn's Star (VZ Pictoris)	202,400	0.291±0.025	Red subdwarf	Closest halo star to the Sun. Previously believed to host an ancient planetary system with potential habitable planets.	^[196]
Stein 2051 A	203,100	0.292±0.031	Red dwarf		^[188]
HD 90089 B	207,300	0.298±0.008			^[157]
HN Librae	208,000	0.299±0.009		Has one confirmed exoplanet.	^[197]
3 Puppis B	210,000	0.3	Hot subdwarf	This star is losing mass to the blue supergiant 3 Puppis A, this mass transfer generates a disk of circumstellar dust around the supergiant, which is unusual for an A-type star.	^[198]
LS Muscae B	~210,000	0.3±0.1	Subdwarf O star		^[191]
Krüger 60 A	209,400	0.301±0.015	Red dwarf		^[130]
Gliese 581	210,100	0.302±0.005		Has three confirmed exoplanets.	^[199]
G 9-40	210,520	0.3026±0.0095		Has one confirmed exoplanets.	^[200]
L 98-59	210,800	0.303+0.026 −0.023		Has four confirmed exoplanets and one unconfirmed.	^[201]
EQ Pegasi B	210,800	0.303±0.013			^[139]
Luyten's Star (Gliese 273)	221,930	0.319±0.004		Has two confirmed exoplanets and two unconfirmed.	^[128]
Wolf 1061	221,930	0.319±0.007		Has three confirmed exoplanets.	^[128]
GJ 3929	223,000	0.32±0.01		Has two confrirmed exoplanets.	^[202]
Xi Ursae Majoris Ab	223,000	0.32			^[147]
Gliese 486 (Gar)	228,190	0.328±0.011		Has one confirmed exoplanet.	^[203]
YZ Canis Minoris	228,190	0.328±0.013			^[128]
FU Tauri B	228,890	0.329±0.031	Brown dwarf		^[204]
LHS 1678	228,890	0.329±0.01	Red dwarf	Has three confirmed exoplanets.	^[205]
Regulus C	231,000	0.332±0.023			^[157]
AM Herculis B	230,000	0.33			^[206]
Wolf 1130 A	230,000	0.33		Nearest candidate for a supernova, a type Ia supernova.^[24]	^[207]
EV Lacertae	230,280	0.331±0.013		On 25 April 2008, a record-setting stellar flare was observed on its surface by NASA's Swift, that was thousands of times more powerful than any solar flare.^[208]	^[128]
Gliese 357	231,670	0.333		Has three confirmed exoplanets.	^[172]
Gliese 667 C	234,450	0.337±0.014		Has two confirmed exoplanets.	^[128]
Aldebaran B	241,410	0.347±0.034			^[148]
Struve 2398 A (Gliese 725 A)	244,200	0.351±0.003		Has one confirmed exoplanet.	^[192]
Gliese 251	253,230	0.364±0.001			^[159]
Ross 458 A	256,020	0.368±0.031		Has one confirmed exoplanet.	^[188]
2MASS 0122–2439 A	257,000	0.369 ± 0.048			^[209]
Furuhjelm 46 B	257,000	0.37±0.07			^[172]
Furuhjelm 46 A	257,000	0.37±0.07			^[172]
Innes' star	258,100	0.371±0.012			^[157]
Gliese 876 (IL Aquarii)	258,800	0.372±0.004		Has four confirmed exoplanets. First red dwarf known to host exoplanets.	^[128]
LHS 6343 A	259,500	0.373±0.005			^[210]
LTT 3780	260,190	0.374±0.011		Has two confirmed exoplanets.	^[211]
Gliese 22 C	261,580	0.376±0.018			^[88]
TOI-270	262,970	0.378±0.011			^[212]
Gliese 1	263,700	0.379±0.002			^[213]
13 Ceti Ab	264,000	0.38			^[147]
GQ Lupi B	264,000	0.38±0.072	Brown dwarf		^[136]
Groombridge 34 A (Gliese 15 A)	267,840	0.385±0.002	Red dwarf		^[128]
Gliese 412 A	272,710	0.398±0.009			^[159]
Lalande 21185	272,710	0.392±0.004			^[128]
Gliese 22 B	274,110	0.394			^[214]
LHS 6343 B	274,110	0.394±0.012			^[210]

275,000 to 350,000 km

Partial list containing stars from 0.395 to 0.5 solar radii.

More information Star name, Star radius, kilometres ...

Star name	Star radius, kilometres	Star radius, R_☉	Star class	Notes	References
Gliese 570 C	277,300	0.399 ± 0.028	Red dwarf		^[143]^[l]
Asellus Primus B (Theta Boötis B)	279,180	0.4013±0.012			^[159]
GJ 3293	281,100	0.404±0.027			^[215]
Gliese 623 A	280,900	0.404 ± 0.024			^[143]^[m]
Alpha Trianguli C	282,500	0.406±0.012			^[157]
Gliese 908 (Lalande 46650)	284,540	0.409±0.023			^[174]
EQ Pegasi A	284,540	0.409±0.016		Has one confirmed exoplanet.	^[139]
Gliese 163	284,540	0.409+0.017 −0.016			^[128]
SDSS J001820.5−093939.2	285,930	0.411+0.090 −0.011	F-type star	Among the most metal-poor stars.	^[216]
Gliese 806	288,300	0.4144±0.0038	Red dwarf	Has three confirmed exoplanets.	^[217]
Gliese 317	290,110	0.4170±0.0013		Has two confirmed exoplanets.	^[159]
Gliese 687	291,290	0.4187^+0.0066 _−0.0063			^[128]
QS Virginis B	292,000	0.42±0.02			^[37]
TOI-700	292,000	0.420±0.031			^[218]
Gliese 180	294,210	0.4229±0.0047		Has two confirmed exoplanets and one unconfirmed.	^[159]
AD Leonis	294,490	0.4233±0.0057			^[219]
Gliese 686	297,060	0.427±0.013			^[220]
Chi Ceti Bb	298,460	0.429±0.017			^[157]
GJ 3634	300,000	0.43±0.03		Has one confirmed exoplanet.	^[221]
Iota Ursae Majoris B	300,000	0.43			^[222]
U Geminorum B	300,000	0.43±0.06			^[223]
Gliese 436	300,540	0.432±0.011		Has one confirmed exoplanet.	^[128]
Gliese 393	300,540	0.432±0.025			^[174]
Sigma Coronae Borealis C	304,020	0.437±0.020			^[139]
Kappa¹ Apodis B	306,000	0.44±0.06	Subdwarf O star		^[191]
WR 93b	306,000	0.44	Wolf-Rayet		^[224]
Gliese 832	307,500	0.442±0.018	Red dwarf		^[128]
Alpha Caeli B	313,000	0.45			^[222]
Gliese 367 (Anañuca)	317,930	0.457±0.013		Has three confirmed exoplanets.	^[225]
Gliese 588	320,000	0.46±0.019			^[128]
Iota Ursae Majoris C	320,000	0.46			^[222]
HD 147379 B	320,000	0.460±0.008			^[226]
Gliese 849	322,800	0.464±0.018			^[128]
BAT99-123 (Brey 93)	327,000	0.47	Wolf-Rayet		^[227]
Gliese 176	329,760	0.474±0.015	Red dwarf		^[128]
Lacaille 9352	329,760	0.474±0.008			^[128]
Tau Boötis B	333,900	0.48±0.05			^[228]
Gliese 752 A	334,630	0.481±0.014			^[220]
UScoCTIO 108 A	336,720	0.484	Brown dwarf		^[229]^[n]
Gliese 526	338,810	0.487±0.008	Red dwarf		^[128]
UX Ursae Majoris B	345,070–484,900	0.496–0.697			^[230]
Theta Persei Ab	346,500	0.498±0.017			^[139]
GJ 3470 (Kaewkosin)	347,150	0.499±0.021			^[128]
Kappa Reticuli B	347,900	0.50			^[231]
TOI-2119	347,900	0.500±0.015			^[127]
Gliese 22 A	~350,000	~0.5			^[232]

Smallest stars by type

More information Type, Star name ...

**List of the smallest stars by star type**
Type	Star name	Radius Solar radii (Sun = 1)	Radius Jupiter radii (Jupiter = 1)	Radius Earth radii (Earth = 1)	Radius (km / mi)	Date	Notes	References
Red dwarf	EBLM J0555−57Ab	0.084	0.84	9.41	60,000 km (37,000 mi)	2017	The red dwarf stars are considered the smallest stars known, and representative of the smallest star possible.	^[233]^[234]^[235]
Brown dwarf	ZTF J1406+1422 B	0.029	0.282	3.16	20,200 kilometres (12,600 mi)	2022	Brown dwarfs are not massive enough to build up the pressure in the central regions to allow nuclear fusion of hydrogen into helium. They are best described as extremely massive gas giants that were not able to ignite into a hydrogen-fusing star.	^[13]
White dwarf	ZTF J1901+1458	0.0031	0.030	0.34	2,140 km (1,330 mi)	2021	White dwarfs are stellar remnants produced when a star with around 8 solar masses or less sheds its outer layers into a planetary nebula. The leftover core becomes the white dwarf. It is thought that white dwarfs cool down over quadrillions of years to produce a black dwarf.	^[15]
Neutron star	RX J0720.4−3125	0.0000064683 – 0.0000077332	0.00006294 – 0.00007525	0.0007055 – 0.0008435	4.50+0.08 −0.09 – 5.38+0.13 −0.14	2012	Neutron stars are stellar remnants produced when stars with around 9 solar masses or more explode in supernovae at the ends of their lives. They are usually produced by stars with less than 20 solar masses, although a more massive star may produce a neutron star in certain cases.	^[2]

Timeline of smallest red dwarf star recordholders

Red dwarfs are considered the smallest stars known that are active fusion stars, and are the smallest stars possible that is not a brown dwarf.

More information Star name, Date ...

**List of smallest red dwarf titleholders**
Star name	Date	Radius Solar radii (Sun = 1)	Radius Jupiter radii (Jupiter = 1)	Radius km (mi)	Notes
EBLM J0555−57Ab	2017-	0.084	0.84	60,000 km (37,000 mi)	This star has a size comparable to that of Saturn.	^[233]^[234]^[235]
2MASS J0523−1403	2013-2017	0.102	1.01	70,600 km (43,900 mi)	Lowest mass main sequence star as of 2020.	^[236]^[89]^[237]^[100]
OGLE-TR-122B	2005-2013	0.117	1.16	81,100 km (50,400 mi)		^[238]^[239]^[132]

Notes

[a]
"Single-star evolution" refer to a star that did not accreted mass from a companion (e.g. a nova) nor formed by the merger of two stars or white dwarfs (e.g. ZTF J1901).
[b]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{11,880}}{\biggr )}^{4}\cdot 10^{-2.88}}}=0.00857\ R_{\odot }$ .
[c]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{58,280}}{\biggr )}^{4}\cdot 10^{0.91}}}=0.02796\ R_{\odot }$ .
[d]
Calculated using surface gravity and mass, via the equation log(R/R_☉) = 2.22 + 0.5 • log(M/M_☉) − 0.5 • log(g).
[e]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{1,840}}{\biggr )}^{4}\cdot 10^{-3.95}}}=0.104\ R_{\odot }$ ${\sqrt {{\biggl (}{\frac {5,772}{1,840}}{\biggr )}^{4}\cdot 10^{-4.04}}}=0.094\ R_{\odot }$ .
[f]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{2,020}}{\biggr )}^{4}\cdot 10^{-3.87}}}=0.095\ R_{\odot }$ ${\sqrt {{\biggl (}{\frac {5,772}{2,020}}{\biggr )}^{4}\cdot 10^{-3.76}}}=0.108\ R_{\odot }$
[g]
Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: ${\sqrt {{\biggl (}{\frac {5,772}{276}}{\biggr )}^{4}\cdot 10^{-7.22}}}=0.1074\ R_{\odot }.$ One $R_{\odot }$ = 9.7311 R_J, so 9.7311 • 0.1074 = 1.045 R_J.
[h]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{2,621}}{\biggr )}^{4}\cdot 10^{-3.22}}}=0.11905\ R_{\odot }$ .
[i]
Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: ${\sqrt {{\biggl (}{\frac {5,772}{2,840}}{\biggr )}^{4}\cdot 10^{-2.986}}}=0.133\ R_{\odot }.$
[j]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{2,925}}{\biggr )}^{4}\cdot 0.0021}}=0.1784\ R_{\odot }$ .
[k]
Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5772 K: ${\sqrt {{\biggl (}{\frac {5772}{3,132}}{\biggr )}^{4}\cdot 10^{-2.337}}}=0.23\ R_{\odot }.$
[l]
Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5772 K: ${\sqrt {{\biggl (}{\frac {5772}{3304}}{\biggr )}^{4}\cdot 10^{-1.768}}}=0.399\ R_{\odot }.$
[m]
Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: ${\sqrt {{\biggl (}{\frac {5,772}{3,400}}{\biggr )}^{4}\cdot 10^{-1.707}}}=0.404\ R_{\odot }.$
[n]
Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{2,700}}{\biggr )}^{4}\cdot 10^{-1.95}}}=0.484\ R_{\odot }$ .

Timeline of smallest red dwarf star recordholders

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