Below are lists of the largest stars currently known, ordered by radius and separated into categories by galaxy. The unit of measurement used is the radius of the Sun (approximately 695,700 km; 432,300 mi).[1]
The angular diameters of stars can be measured directly using stellar interferometry. Other methods can use lunar occultations or from eclipsing binaries, which can be used to test indirect methods of finding stellar radii. Only a few useful supergiant stars can be occulted by the Moon, including Antares A (Alpha Scorpii A). Examples of eclipsing binaries are Epsilon Aurigae (Almaaz), VV Cephei, and V766 Centauri (HR 5171). Angular diameter measurements can be inconsistent because the boundary of the very tenuous atmosphere (opacity) differs depending on the wavelength of light in which the star is observed.
Uncertainties remain with the membership and order of the lists, especially when deriving various parameters used in calculations, such as stellar luminosity and effective temperature. Often stellar radii can only be expressed as an average or be within a large range of values. Values for stellar radii vary significantly in different sources and for different observation methods.
All the sizes stated in these lists have inaccuracies and may be disputed. The lists are still a work in progress and parameters are prone to change.
Various issues exist in determining accurate radii of the largest stars, which in many cases do display significant errors. The following lists are generally based on various considerations or assumptions; these include:
The following lists show the largest known stars based on the host galaxy.
![]() | This list is incomplete; you can help by adding missing items. (January 2016) |
Star name | Solar radii (Sun = 1) |
Method[lower-alpha 1] | Notes |
---|---|---|---|
Stephenson 2-18 | 2,150[4] | L/Teff | Located in close proximity to the extremely massive open cluster Stephenson 2 (RSGC2), where 25 other red supergiants are also located. Membership in the cluster currently uncertain, with large uncertainties in the measurements. |
Orbit of Saturn | 2,047–2,049.9[5][lower-alpha 2] | Reported for reference | |
UY Scuti | 1,708±192[6] | AD | The radius of UY Sct is more extreme than what current stellar evolution models predict. One paper mentions this extremity, and the reason for it is not yet clear.[7] |
RSGC1-F01 | 1,530[8] | L/Teff | |
The above radii are larger than what stellar evolution theory predicts, and are thus potentially unreliable | |||
Theoretical limit of star size (Milky Way) | ~1,500[9] | This value comes from the rough average radii of the three largest stars studied in the paper. It is consistent with the largest possible stellar radii predicted from the current evolutionary theory, and it is believed that stars above this radius would be too unstable and simply do not form.[9] Reported for reference | |
RSGC1-F04 | 1,422[8] | L/Teff | |
VY Canis Majoris | 1,420±120[10] | AD | |
KY Cygni | 1,420±284–(2,850±570)[9] | L/Teff | |
CM Velorum | 1,416.2385+0.3981 −0.9623[11] |
L/Teff | |
AH Scorpii | 1,411±124[6] | AD | |
RSGC1-F06 | 1,382[8] | L/Teff | |
CD-26 5055 | 1,279.8291+20.4064 −122.9196[11] |
L/Teff | |
AS Cephei | 1,262.5137+18.8257 −8.6085[11] |
L/Teff | |
RSGC1-F10 | 1,246[8] | L/Teff | |
Westerlund 1 W237 (Westerlund 1 BKS B) | 1,241±70[12] | L/Teff | |
IRC -10414 | ~1,200[13] | L/Teff | |
V517 Monocerotis | 1,196.2521+79.7298 −158.8974[11] |
L/Teff | |
PZ Cassiopeiae | 1,190±238(–1,940±388)[9] | L/Teff | |
BC Cygni | 1,186.6136+33.6601 −37.1276[11] |
L/Teff | A more detailed but older study gives values of 1,081 R☉ (856–1,375) for the year 2000, and 1,303 R☉ (1,021–1,553) for the year 1900.[14] |
RSGC1-F05 | 1,185[8] | L/Teff | |
NML Cygni | 1,183[15] | L/Teff | |
GCIRS 7 | 1,170±60[16]–1,368[17] | AD | |
Westerlund 1 W26 (Westerlund 1 BKS AS) | 1,165±58–1,221±120[12] | L/Teff | |
RSGC1-F08 | 1,150[8] | L/Teff | |
RSGC1-F02 | 1,128[8] | L/Teff | |
Orbit of Jupiter | 1,114.5–1,115.8[5][lower-alpha 2] | Reported for reference | |
V766 Centauri Aa | 1,110±50[18] | ? | V766 Centauri Aa is a rare variable yellow supergiant. |
RT Carinae | 1,090±218[9] | L/Teff | |
UU Persei | 1,078.8212+8.5103 −8.2887[11] |
L/Teff | |
V396 Centauri | 1,070±214[9] – 1,145.31[19] | L/Teff & ? | |
HD 126577 | 1,065.5137+8.6624 −31.799[11] |
L/Teff | |
W Persei | 1,052.6853+76.7502 −85.3499[11] |
L/Teff | |
V602 Carinae | 1,050±165[20] | AD | |
RSGC1-F11 | 1,035[8] | L/Teff | |
RSGC1-F13 | 1,017[8] | L/Teff | |
CK Carinae | 1,013.42 – 1,060±212[9] | L/Teff | |
KW Sagittarii | 1,009±142[6] | AD | |
RSGC1-F07 | 1,006[8] | L/Teff | |
V349 Carinae | 1,001.6769+12.0794 −73.6583[11] |
L/Teff | |
RSGC1-F09 | 996[8] | L/Teff | |
RSGC1-F12 | 955[8] | L/Teff | |
RSGC1-F03 | 942[8] | L/Teff | |
AZ Cygni | 911+57 −50[21] |
AD | |
NSV 25875 | 891[15] | L/Teff | |
V437 Scuti | 874[15] | L/Teff | |
LL Pegasi | 869[15] | L/Teff | |
V669 Cassiopeiae | 859[15] | L/Teff | |
Westerlund 1 W20 (Westerlund 1 BKS D) | 858±48[12] | L/Teff | |
VX Sagittarii | 853[15]-1,335±215[22] | L/Teff | |
BI Cygni | 851.14[23]–1,240±248[9] | L/Teff | |
μ Cephei (Herschel's Garnet Star) | 830[15]-972±228[24] | AD | |
V1185 Scorpii | 830[15] | L/Teff | |
CW Leonis | 826[15] | L/Teff | |
LP Andromedae | 815[15] | L/Teff | |
U Arietis | 801±205[25] | AD | |
RT Ophiuchi | 801±217[26] | AD | |
BO Carinae | 790±158[9] | L/Teff | |
S Persei | 780±156(–1,230±246)[9] | L/Teff | |
SU Persei | 780±156[9] – 971.405[19] | L/Teff | |
RS Persei | 770±30[27] | AD | |
V355 Cephei | 770±154[9] | L/Teff | |
GU Cephei A | 766.486[19] | ? | |
Betelgeuse (α Orionis) | 764+116 −62[28] |
? | Tenth brightest star in the night sky.[29] |
HD 303250 | 750±150[9] | L/Teff | |
UU Pegasi | 742±193[26] | AD | |
Westerlund 1 W75 (Westerlund 1 BKS E) | 722±36[12] | L/Teff | |
V Camelopardalis | 716±185[26] | AD | |
V923 Centauri | 715.539[19] | ? | |
V528 Carinae | 700±140[9] | L/Teff | |
The following well-known stars are listed for the purpose of comparison. | |||
V354 Cephei | 685[30] | L/Teff | |
Antares A (α Scorpii) | 680[31] | AD | Fourteenth brightest star in the night sky.[29] |
Mira A (ο Ceti) | 541[15] | L/Teff | |
Unurgunite (σ Canis Majoris) | 420±84[9] | L/Teff | |
Orbit of Mars | 322–323.1[5][lower-alpha 2] | Reported for reference | |
Pistol Star (V4647 Sagittarii) | 306[32] | ? | |
Rasalgethi A (α Herculis) | 284±60 (264–303)[33] | L/Teff | |
Wezen (δ Canis Majoris) | 215±66[34] | AD | Thirty-sixth brightest star in the night sky.[29] |
Orbit of Earth (~1 AU) | 214[5][lower-alpha 2] | Reported for reference | |
Enif (ε Pegasi) | 210.37 – 210.69[35] | ? | |
Suhail (λ Velorum) | 210[36] | ? | |
Deneb (α Cygni) | 203±17[37] | ? | Eighteenth brightest star in the night sky.[29] |
Orbit of Venus | 158.6[5][lower-alpha 2] | Reported for reference | |
Orbit of Mercury | 82.9–84.6[5][lower-alpha 2] | Reported for reference | |
Vega (α Lyrae) | 2.726±0.006 × 2.418±0.012[38] | Fifth brightest star in the night sky.[29] Reported for reference | |
Sun | 1 | The largest object in the Solar System. Reported for reference |
Star name | Solar radii (Sun = 1) |
Galaxy | Method[lower-alpha 1] | Notes |
---|---|---|---|---|
LI-LMC 60 | 1,765[39] | Large Magellanic Cloud | L/Teff | |
WOH G64 | 1,540[40] | Large Magellanic Cloud | L/Teff | Surrounded by a large dust cloud. |
W60 B90 (WOH S264) | 1,390+130 −110[41] |
Large Magellanic Cloud | L/Teff | Further investigation is needed to constrain the luminosity and radius with more certainty.[41] |
UCAC2 2674864 (HV 2834) | 990+115 −100[41] |
Large Magellanic Cloud | L/Teff | |
HV 12185 | 890+55 −65[41] |
Large Magellanic Cloud | L/Teff | |
HV 12793 | 880+45 −65[41] |
Large Magellanic Cloud | L/Teff | |
WOH S57 | 875+70 −60[41] |
Large Magellanic Cloud | L/Teff | |
SP77 28-2 | 825±60[41] | Large Magellanic Cloud | L/Teff | |
W61 19-24 | 780+50 −70[41] |
Large Magellanic Cloud | L/Teff | |
PMM4 64 | 730+75 −65[41] |
Small Magellanic Cloud | L/Teff | |
WOH S374 | 610+75 −60[41] |
Large Magellanic Cloud | L/Teff | |
Star name | Solar radii (Sun = 1) |
Galaxy | Method[lower-alpha 1] | Notes |
---|---|---|---|---|
LGGS J004124.80+411634.7 | 1,240[42] | Andromeda Galaxy | L/Teff | |
LGGS J004035.08+404522.3 | 1,230[42] | Andromeda Galaxy | L/Teff | |
LGGS J004047.82+410936.4 | 1,010[42] | Andromeda Galaxy | L/Teff | |
LGGS J004424.94+412322.3 | 945[42] | Andromeda Galaxy | L/Teff | |
LGGS J004501.30+413922.5 | 910[42] | Andromeda Galaxy | L/Teff | |
LGGS J004447.08+412801.7 | 825[42] | Andromeda Galaxy | L/Teff | |
LGGS J004255.95+404857.5 | 785[42] | Andromeda Galaxy | L/Teff | |
LGGS J003913.40+403714.2 | 640[42] | Andromeda Galaxy | L/Teff | |
LGGS J004428.71+420601.6 | 605[42] | Andromeda Galaxy | L/Teff | |
LGGS J004607.45+414544.6 | 560[42] | Andromeda Galaxy | L/Teff | |
LGGS J003902.20+403907.3 | 525[42] | Andromeda Galaxy | L/Teff | |
LGGS J003857.29+404053.6 | 500[42] | Andromeda Galaxy | L/Teff |
|
Star name | Solar radii (Sun = 1) |
Galaxy | Method[lower-alpha 1] | Notes
|
---|---|---|---|---|
Sextans A 10 | 995±130[43] | Sextans A | L/Teff | |
Sextans A 5 | 870±145[43] | Sextans A | L/Teff | |
LeoA 7 | 786.5[44] | Leo A | L/Teff | |
Sextans A 7 | 710±100[43] | Sextans A | L/Teff | |
IC 10 3 | 685±90[43] | IC 10 | L/Teff | |
WLM 14 | 610±80[43] | WLM | L/Teff | |
Sextans B 1 | 565±70[43] | Sextans B | L/Teff | |
IC 1613 2 | 560±70[43] | IC 1613 | L/Teff | |
WLM 12 | 430±70[43] | WLM | L/Teff | |
IC 10 5 | 420±50[43] | IC 10 | L/Teff | |
Sextans B 2 | 405±90[43] | Sextans B | L/Teff | |
LeoA 75 | 404.4[44] | Leo A | L/Teff | |
WLM 13 | 380±50[43] | WLM | L/Teff | |
LeoA 90 | 353.9[44] | Leo A | L/Teff | |
LeoA 143 | 353.7[44] | Leo A | L/Teff | |
Sextans A 6 | 350±40[43] | Sextans A | L/Teff | |
Pegasus 1 | 340±50[43] | Pegasus Dwarf | L/Teff | |
Sextans A 4 | 335±40[43] | Sextans A | L/Teff | |
WLM 11 | 310±50[43] | WLM | L/Teff | |
IC 1613 1 | 300±40[43] | IC 1613 | L/Teff | |
IC 10 2 | 280±30[43] | IC 10 | L/Teff | |
Pegasus 2 | 260±40[43] | Pegasus Dwarf | L/Teff | |
Sextans A 8 | 260±60[43] | Sextans A | L/Teff | |
LeoA 203 | 244[44] | Leo A | L/Teff | Known red supergiant[45] |
Sextans A 9 | 230±50[43] | Sextans A | L/Teff | |
LeoA 98 | 211.2[44] | Leo A | L/Teff | |
IC 10 4 | 200±25[43] | IC 10 | L/Teff | |
IC 10 1 | 165±60[43] | IC 10 | L/Teff | |
IC 10 6 | 160±25[43] | IC 10 | L/Teff | |
Phoenix 3 | 90±15[43] | Phoenix Dwarf | L/Teff |
Star name | Solar radii (Sun = 1) |
Galaxy | Group | Method[lower-alpha 1] | Notes |
---|---|---|---|---|---|
NGC 2363-V1 | 194–356[46] | NGC 2363 | M81 Group | L/Teff |
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Properties |
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Earth-centric observations |
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