List of largest stars

Below is a list of the largest stars, so far discovered, ordered by radius. The unit of measurement used is the radius of the Sun (695,700 km; 432,287.938 mi).

Additional methods
A few stars are in the Zodiac, and the Moon sometimes passes in front of them. This allows calculating their size by their angular size and distance. Most do not, so astronomers calculate their size by their spectral type (which gives their luminosity), distance, and brightness. Other stars can have their apparent diameter measured by an interferometer; If the star's distance is known, the real size can be found.

 Caveats 
These objects are extremely big, thousand to millions of times the volume of our Sun, and extremely luminous. These stars also have extended atmospheres and photospheres, and are often shrouded in dust. This makes their true size uncertain. Many of these stars vary in size and brightness (like Betelguese, Antares, Mu Cephei and VY Canis Majoris). Galaxies have different properties that affect how large their stars can be. This is why there are separate lists for galaxies.

These objects are far away, sometimes intergalactic (eg: WOH G64
is in the Large Magellanic Cloud). This makes it even harder to calculate their sizes. Most stars found will not be above 1,500 times the Sun's radius. Their mass would hardly hold together, and a lot of material would be ejected by powerful solar winds, forming the nebulae we see around them.

Astrophysicist Robert F. Wing did an in-depth look on the largest stars, recognising Antares, Betelgeuse, Mu Cephei, and VV Cephei A as well-accepted largest stars, while also looking at other stars known for cool temperatures and high brightness like VY Canis Majoris and NML Cygni. The Stefan–Boltzmann law says these stars would have a large size.

While red supergiants and hypergiants are usually the largest stars, some stars can increase their size for a short time before shrinking again. This process is called an eruption. Some eruptions, like those of Eta Carinae and V838 Monocerotis, made them much larger than the largest stars for a short time. These are listed separately.

List 
 Milky Way 

+List of the largest stars in the Milky Way Galaxy Star name Solar radii(Sun = 1) Method Notes Orbit of Saturn  1,940—2,169   Reported for referenceWOH G64 A1,540 ± 77L/TeffLocated in the Large Magellanic Cloud. Reported for referenceRSGC1-F01 1,450– L/TeffLocated in the massive open cluster RSGC1.Mu Cephei1,420L/TeffAlso known as Herschel's Garnet Star. VY Canis Majoris  1,420 AD  Older estimates originally estimated the radius of VY CMa to be above , or as little as . The  measure has a margin of error of . AH Scorpii  1,411  AD  AH Sco is a variable by nearly 3 magnitudes in the visual range, and an estimated 20% in total luminosity. The variation in diameter is not clear because the temperature also varies.V766 Centauri Aa1,315 ± 260https://www.aanda.org/articles/aa/abs/2014/03/aa22421-13/aa22421-13.htmlADV766 Centauri Aa is a highly distorted star in a close binary system, losing mass to the secondary. It is also variable in temperature, thus probably also in diameter. Other estimates range from 1,060-1,160 solar radii to 1,490 ± 540 solar radii.S Persei 1,298 L/Teff A red supergiant located in the Perseus Double Cluster. Levsque et al. 2005 calculated radii of  and  based on K-band measurements.Table 4 in  Older estimates gave up to  based on higher luminosities.RW Cygni1,273AD PZ Cassiopeiae   1,259–1,336 L/Teff Westerlund 1-237 1,245 L/TeffRed supergiant within the Westerlund 1 super star cluster. IRC -10414  1,200  L/Teff  IRC -10414 is a rare red supergiant companion to WR 114 that has a bow shock.HD 905871,181ADRSGC1-F03  1,168-1,326 L/TeffLocated in the massive open cluster RSGC1. EV Carinae  1,168  L/Teff  Older estimates based on much larger distances have given higher luminosities, and consequently larger radii.Westerlund 1-261,165 or 1,221 L/Teff Very uncertain parameters for an unusual star with strong radio emission. The spectrum is variable but apparently the luminosity is not.HD 143183 (V558 Normae)1,147ADV602 Carinae1,142AD MY Cephei  1,135  L/Teff  Not to be confused with Mu Cephei (see above). Older estimates have given up to  based on much cooler temperatures.HV 2561 1,133 L/Teff Located in the Large Magellanic Cloud J004035.08+404522.3  1,130-1,230 L/Teff  Located in the Andromeda Galaxy RSGC1-F021,128-1,549L/TeffLocated in the massive open cluster RSGC1. VX Sagittarii  1,120-1,550 L/Teff  VX Sgr is a pulsating variable with a large visual range and is calculated to vary in size from  to . Widely known as one of the largest known stars. RSGC1-F08  1,088-1,146 L/TeffLocated in the massive open cluster RSGC1.Trumpler 27-11,073L/Teff Orbit of Jupiter  1,064-1,173   Reported for referenceVV Cephei A1,050EBVV Cep A is a highly distorted star in a close binary system, losing mass to the secondary for at least part of its orbit. Data from the most recent eclipse has cast additional doubt on the accepted model of the system. Older, disproven estimates give up to 1,800 solar radii. Widely known as one of the largest known stars.SU Persei1,039ADIn the Perseus Double ClusterKY Cygni1,033-1,420L/TeffRW Leonis Minoris1,028L/TeffAlso called CIT (California Institute of Technology) 6. RSGC1-F12  1,005  L/Teff Located in the massive open cluster RSGC1.RT Carinae995ADRSGC1-F13  993-1,098 L/TeffLocated in the massive open cluster RSGC1.RSGC1-F09  986-1,231 L/TeffLocated in the massive open cluster RSGC1. NR Vulpeculae  980  L/Teff Westerlund 1-20965L/TeffRed supergiant within the Westerlund 1 super star cluster.V396 Centauri965AD GCIRS 7  960-1,368 AD  Located at the galactic center. Margin of possible error:  or .RSGC1-F11  955-1,015 L/TeffLocated in the massive open cluster RSGC1.V341 Lacertae953ADHD 155737951AD SMC 50840  950  L/Teff HU Puppis950ADHV 894946L/Teff J004424.94+412322.3  945-1,300 L/Teff  Located in the Andromeda Galaxy.RM 1-361933L/TeffHV 916 932 L/Teff Located in the Large Magellanic CloudRSGC1-F10  931-954 L/TeffLocated in the massive open cluster RSGC1. S Cassiopeiae  930 DSKEWOH S71926L/Teff IX Carinae  920  L/Teff  HV 2112  916  L/Teff  Most likely candidate for a Thorne-Żytkow object. RSGC1-F04  914-1,082 L/TeffLocated in the massive open cluster RSGC1.UY Scuti909L/TeffRW Cephei900-1760L/Teff IRAS 04498-6842  900 L/Teff  Located in the Large Magellanic Cloud LMC 54365  900  L/Teff  Located in the Large Magellanic Cloud HV 996  894  L/Teff  Located in the Large Magellanic Cloud NSV 25875  891 L/Teff LMC 1318891L/TeffProbably the largest AGB Star. HV 12501  890  L/Teff  Located in the Large Magellanic Cloud LMC 109106  890  L/Teff  Located in the Large Magellanic CloudRSGC1-F06  885-967 L/TeffLocated in the massive open cluster RSGC1.Stephenson 2-11884L/TeffIRC -20412882AD IRAS 05558-7000  880  L/Teff  Located in the Large Magellanic Cloud SMC 30616  880  L/Teff  LMC 64048  880  L/Teff  Located in the Large Magellanic Cloud V437 Scuti  874  L/Teff  IRAS 04407-7000  870  L/Teff  Located in the Large Magellanic Cloud IRAS 05329-6708  870  L/Teff  Located in the Large Magellanic CloudSMC 46662868L/Teff HV 986  867  L/Teff  Located in the Large Magellanic Cloud J004047.82+410936.4  860-1,010 L/Teff  Located in the Andromeda Galaxy AZ Cygni861ADAZ Cephei860AD V669 Cassiopeiae  859  L/Teff  HV 2360  857  L/Teff  Located in the Large Magellanic Cloud HV 5870  856  L/Teff  Located in the Large Magellanic Cloud BI Cygni  850-1,240 L/Teff SMC 15510 850 L/Teff KW Sagittarii850ADOlder estimates have given larger radii and consequently cooler temperatures.V353 Puppis824ADUW Aquilae823ADStephenson 2-14821L/TeffBC Cygni 820 L/Teff  V362 Aurigae819ADLMC 116895814L/TeffLocated in the Large Magellanic Cloud LMC 142199  810  L/Teff  Located in the Large Magellanic Cloud IRAS 05294-7104  810  L/Teff  Located in the Large Magellanic CloudPMMR 41809L/TeffHD 268850808L/TeffYZ Persei 804 AD LMC 134383802L/TeffLocated in the Large Magellanic Cloud IRAS 05402-6956  800  L/Teff  Located in the Large Magellanic Cloud V441 Persei  799  L/Teff PMMR 34796L/Teff BU Persei  795  L/Teff  BO Carinae  790  L/Teff  IRAS 05298-6957  790  L/Teff  Located in the Large Magellanic Cloud LMC 142907  790  L/Teff  Located in the Large Magellanic CloudV641 Cassiopeiae788ADHV 963787L/Teff6 Geminorum (BU Geminorum)787ADU Lacertae 785 L/Teff SMC 11709 781 L/Teff RS Persei  770-831 AD & L/Teff  In the Perseus Double Cluster. Margin of possible error: . AV Persei  770  L/Teff  In the Perseus Double Cluster V355 Cephei  770  L/Teff  Mauron et al. 2011 derive , which implies a size around .V517 Monocerotis768ADHD 303250 766 AD PMMR 141762L/TeffHV 2551762L/TeffSMC 52334761L/Teff J004124.80+411634.7  760-1,240 L/Teff  Located in the Andromeda Galaxy and has a possible hot companion. V915 Scorpii  760  L/Teff  S Cephei  760  AD HD 95687758AD J004447.08+412801.7  755-825 L/Teff  Located in the Andromeda Galaxy Psi1 Aurigae753ADA red supergiant similar to Antares and Betelgeuse (see below), but much further away. Outer limits of the asteroid belt  750-900   Reported for reference SMC 11939  750  L/Teff  R Cygni  745  L/Teff  RU Virginis  740  L/Teff  LMC 137818  740  L/Teff  Located in the Large Magellanic Cloud SMC 48122  740  L/Teff V923 Centauri736AD IRAS 04545-7000  730  L/Teff  Located in the Large Magellanic Cloud IRAS 05003-6712  730  L/Teff  Located in the Large Magellanic Cloud SMC 56732  730  L/Teff  WOH SG374  730  L/Teff GU Cephei730AD KK Persei  724  L/Teff AD Persei724L/TeffRSGC1-F07  718-910 L/TeffLocated in the massive open cluster RSGC1. XX Persei  710  L/Teff  Located in the Perseus Double Cluster and near the border with Andromeda. V648 Cassiopeiae  710  L/Teff Stephenson 2-04710L/TeffMercer 8-06707L/TeffHV 1652706L/Teff HD 179821  704 DSKE HD 179821 may be a yellow hypergiant or a much less luminous star.SMC 55681704L/TeffV407 Puppis703AD J004255.95+404857.5  700-785 L/Teff  Located in the Andromeda Galaxy V528 Carinae  700  L/Teff  J003950.98+405422.5  700  L/Teff  Located in the Andromeda Galaxy  LMC 169754  700  L/Teff  Located in the Large Magellanic Cloud LMC 65558  700  L/Teff  Located in the Large Magellanic Cloud SP77 30-6 (WOH S66)  700  L/Teff V770 Cassiopeiae700AD The following notable stars with sizes below 700 solar radii are kept here for comparisonAntares (Alpha Scorpii A)680 (varies by 19%)ADAntares was once thought to be over , but those estimates are likely to have been affected by asymmetry of the atmosphere of the star. Widely known as one of the largest known stars.Betelgeuse (Alpha Orionis)~640-697ADStar with the third largest apparent size after R Doradus and the Sun. Another estimate gives  This estimate might not be reliable due to problems with measuring red supergiants in this way, but is consistent with other size estimates. Betelgeuse is a variable star so it changes size often. Widely known as one of the largest known stars.Rho Cassiopeiae 636-981  AD Yellow hypergiant, one of the rarest types of a star.Orbit of Ceres602.09Reported for reference V509 Cassiopeiae (HR 8752) 590 AD Yellow hypergiant, one of the rarest types of a star. CE Tauri  587-593 (-608)  AD  Can be occulted by the Moon, allowing accurate determination of its apparent diameter.V382 Carinae 471ADYellow hypergiant, one of the rarest types of a star.V838 Monocerotis467L/TeffA short time after the outburst V838 Mon was measured at , but its distance, and hence its size, have since been reduced and it proved to be a transient object that shrunk about four-fold over a few years. Like CW Leo, it has been erroneously portrayed as "Nibiru" or "Planet X" (see below).The Pistol Star420ADBlue hypergiant, among the most massive and luminous stars known. Inner limits of the asteroid belt  380   Reported for reference Mira A (Omicron Ceti)  332-402 AD  Prototype Mira variable. De beck et al. 2010 calculates .R Doradus298AD Star with the second largest apparent size after the Sun. Orbit of Mars  297-358   Reported for referenceLa Superba (Y Canum Venaticorum) 289 AD  Referred to as La Superba by Angelo Secchi. Currently one of the coolest and reddest stars. Sun's red giant phase (asymptotic giant branch)  256   At this point, the Sun will engulf Mercury and Venus, and possibly the Earth although it will move away from its orbit since the Sun will lose a third of its mass. During the helium burning phase, it will shrink to  but will later grow again and become an unstable AGB star, and then a white dwarf after making a planetary nebula. Reported for reference Eta Carinae A  ~240   Previously thought to be the most massive single star, but in 2005 it was realized to be a binary system. η Car lacks a good surface as the wind from it is so thick. It has a "core" with a radius of  and the edge of the wind has a radius of . Orbit of Earth  215 (211-219)   Reported for reference Orbit of Venus  154-157   Reported for reference Epsilon Aurigae A (Almaaz)  143-358 AD  ε Aur was incorrectly claimed in 1970 as the largest star with a size between  and , even though it later turned out not to be an "infrared light star" but rather a dusk torus surrounding the system.Deneb (Alpha Cygni) 99.84 AD  Prototype Alpha Cygni variable. WR 102ka 92  AD  Candidate for most luminous star in the Milky Way.Rigel78.9Brightest star in Orion. Canopus (Alpha Carinae)  71  AD  Second brightest star in the night sky. Orbit of Mercury  66-100   Reported for referenceAlbireo (Beta Cygni A)62Red giant in the Cygnus constellation that is part of a binary system. LBV 1806-20  46-145 L/Teff  Formerly a candidate for the most luminous star in the Milky Way with , but the luminosity has been revised later only . Aldebaran (Alpha Tauri)  43.06 AD  Close red giant star. Polaris (Alpha Ursae Minoris) 37.5  AD  The current northern pole star and a well-known Cepheid variable. Arcturus (Alpha Boötis)  24.25 AD  Brightest star in the northern hemisphere, and a K-type red giant. HDE 226868  20-22 Note: For radius, see Table 1 with d=2 kpc.  The supergiant companion of black hole Cygnus X-1. The black hole is around 500,000 times smaller than the star. Dubhe (Alpha Ursae Majoris)  17.03  AD  A red giant star in the prominent Ursa Major constellation. VV Cephei B  13–25   The blue main-sequence star companion of VV Cephei A.Pollux (Beta Geminorum)9.06 ± 0.03 The nearest giant star to Earth.Regulus (Alpha Leonis)4.35 ± 0.1The nearest B-type star to Earth. Vega (Alpha Lyrae) 2.726±0.006 × 2.418±0.012 One of the brightest stars in the night sky.Sirius A (Alpha Canis Majoris A)1.711The brightest star in the night sky.Alpha Centauri A1.2175Nearest G-type yellow dwarf to the Sun. Sun  1   The largest object in the Solar System.Reported for reference

 Magellanic Clouds 
Star nameSolar radii
(Sun = 1)MethodNotesWOH G64 A1,540 ± 77L/TeffLocated in the Large Magellanic Cloud.HV 888 (WOH S140)1,509L/TeffLocated in the Large Magellanic Cloud.WOH S2811,376L/TeffHV 114231,086L/TeffLocated in the Small Magellanic Cloud. HV 11423 is variable in spectral type (observed from K0 to M5), thus probably also in diameter. In October 1978, it was a star of M0I type.SMC 018136945L/TeffHV 986867The following notable stars with sizes below 700 solar radii are kept here for comparisonHV 2112675-1,193L/TeffOnce thought to be a possible Thorne–Żytkow object, or a red supergiant with a neutron star core.HD 269953647-720A yellow hypergiant.HD 33579471L/TeffThe brightest star in the Large Magellanic Cloud.S Doradus100-380L/TeffA notable blue hypergiant among the most luminous stars known.HD 3797499L/TeffA blue hypergiant with a dusty disk.R136a128.8-35.4ADOne of the most massive and luminous stars known ( and around ).BAT99-9837.5L/TeffOne of the most massive and luminous stars known.HD 5980 A24L/TeffOne of the most massive and luminous stars known.

 Outside the Local Group 
Star nameSolar radii
(Sun = 1)GalaxyMethodNotes NGC 2403 V141,260NGC 2403F-type star.Quyllur965L/TeffDistant red supergiant that the James Webb Space Telescope saw.Godzilla430-2,365Sunburst GalaxyThe most luminous star ever known, at up to 255 million times brighter than the Sun.Mothra271A binary star.NGC 2363-V1194-356NGC 2366L/Teff

 Eruptions (temporary sizes) 
Star nameSolar radii
(Sun = 1)YearGalaxyMethodNotes AT 2017jfs33,0002017NGC 4470L/TeffSNhunt15116,7002014UGC 3165L/TeffOrbit of Neptune~6,500https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%278%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272000-01-01%27&STOP_TIME=%272000-01-02%27&STEP_SIZE=%27200%20years%27&CENTER=%27@0%27&OUT_UNITS=%27AU-D%27Reported for referenceM51 OT2019-15,4862019Whirlpool GalaxyL/TeffEta Carinae4,319-6,0321845Milky WayL/TeffDuring this time, it became the second-brightest star in the night sky.Orbit of Uranus4,121.7-4,126.3Reported for referenceV838 Monocerotis3,1902002Milky WayL/TeffPHL 293B's luminous blue variable1,348–1,4632002PHL 293BL/TeffThis star, a blue supergiant, may not exist anymore.R715002012Large Magellanic CloudL/TeffGodzilla430-2,3652015Sunburst GalaxyL/Teff

Related pages
List of most massive stars
List of most luminous stars

References

Category:Lists of stars