<Li> Some red supergiants in the Magellanic Clouds are suspected to have slightly different limiting temperatures and luminosities . Such stars may exceed accepted limits by undergoing large eruptions or change their spectral types over just a few months . Humphreys et al., for example, calculates the maximum size for a Magellanic cloud star as ~ 2,600 R . </Li> <Li> A survey of the Magellanic Clouds has catalogued many red supergiants, where more than 50 of them exceed 700 R (490,000,000 km; 3.3 AU; 300,000,000 mi). Largest of these is about 1,200 - 1,300 R . </Li> <Table> List of the largest stars <Tr> <Th> Star name </Th> <Th> Solar radii (Sun = 1) </Th> <Th> Method </Th> <Th> Notes </Th> </Tr> <Tr> <Td> Orbit of Saturn </Td> <Td> 1,940--2,169 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> UY Scuti </Td> <Td> 1,708 ± 192 </Td> <Td> AD </Td> <Td> Margin of error in size determination: ± 192 solar radii . At the smallest, it would have a size similar to VX Sagittarii (see below) </Td> </Tr> <Tr> <Td> WOH G64 </Td> <Td> 1,540--1,730 </Td> <Td> L / T </Td> <Td> This would be the largest star in the LMC, but is unusual in position and motion and might still be a foreground halo giant . </Td> </Tr> <Tr> <Td> RW Cephei </Td> <Td> 1,535 </Td> <Td> L / T </Td> <Td> RW Cep is variable both in brightness (by at least a factor of 3) and spectral type (observed from G8 to M), thus probably also in diameter . Because the spectral type and temperature at maximum luminosity are not known, the quoted size is just an estimate . </Td> </Tr> <Tr> <Td> Westerlund 1 - 26 </Td> <Td> 1,530 - 1,580 (--2,550) </Td> <Td> L / T </Td> <Td> Very uncertain parameters for an unusual star with strong radio emission . The spectrum is variable but apparently the luminosity is not . </Td> </Tr> <Tr> <Td> KY Cygni </Td> <Td> 1,420--2,850 </Td> <Td> L / T </Td> <Td> The upper estimate is due to an unusual K band measurement and thought to be an artifact of a reddening correction error, and is thought to be against stellar evolutionary theory . The lower estimate is consistent with other stars in the same survey and with theoretical models . </Td> </Tr> <Tr> <Td> VY Canis Majoris </Td> <Td> 1,420 ± 120 </Td> <Td> AD </Td> <Td> Humphreys et al previously estimated the radius of VY CMa to be 1,800 R to 2,200 R; a size so large that places it outside the bounds of stellar evolutionary theory . Improved measurements have brought it down to size . This star is a red hypergiant, although Massey et al. considered it as a normal red supergiant with a radius of only 600 R . </Td> </Tr> <Tr> <Td> AH Scorpii </Td> <Td> 1,411 ± 124 </Td> <Td> AD </Td> <Td> AH Sco is 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 . </Td> </Tr> <Tr> <Td> VV Cephei A </Td> <Td> 1,400, 1,050--1,900 </Td> <Td> </Td> <Td> VV Cep A is a highly distorted star in a close binary system, losing mass to the secondary for at least part of its orbit . Other estimates give a range from 1,200 R to 1,600 R . </Td> </Tr> <Tr> <Td> RSGC1 - F02 </Td> <Td> 1,398 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F01 </Td> <Td> 1,335 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> HR 5171 A </Td> <Td> 1,315 ± 260, 1,575 ± 400 </Td> <Td> AD </Td> <Td> HR 5171 A is a highly distorted star in a close binary system, losing mass to the secondary, and is also variable in temperature, thus probably also in diameter . Traditionally, it is considered as the largest known yellow hypergiant, although the latest research suggests it is a red supergiant with a radius 1,490 ± 540 R . </Td> </Tr> <Tr> <Td> SMC 18136 </Td> <Td> 1,310 </Td> <Td> </Td> <Td> This would be the largest star in the SMC . </Td> </Tr> <Tr> <Td> PZ Cassiopeiae </Td> <Td> 1,260 - 1,340, 1,190 - 1,940 </Td> <Td> L / T </Td> <Td> The largest estimate is due to an unusual K band measurement and thought to be an artifact of a reddening correction error . The lowest estimate is consistent with other stars in the same survey and with theoretical models, and the intermediate ones have been obtained refining the distance to this star, and thus its parameters . </Td> </Tr> <Tr> <Td> Mu Cephei (Herschel's "Garnet Star") </Td> <Td> 1,260 </Td> <Td> </Td> <Td> Reddest star in the night sky . Other recent estimates range from 650 R to 1,420 R </Td> </Tr> <Tr> <Td> LMC 136042 </Td> <Td> 1,240 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> BI Cygni </Td> <Td> 1,240 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> Westerlund 1 - 237 </Td> <Td> 1,233 </Td> <Td> L / T </Td> <Td> Calculated from an effective temperature of 3,600 K and a luminosity of 230,000 L . </Td> </Tr> <Tr> <Td> SMC 5092 </Td> <Td> 1,220 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> S Persei </Td> <Td> 1,212 ± 124 </Td> <Td> AD & L / T </Td> <Td> A red hypergiant localed in the Perseus Double Cluster . A large radius of 1,230 R is due to an unusual K band measurement and thought to be an artifact of a reddening correction error . A small radius of 780 R is consistent with other stars in the same survey and with theoretical models . </Td> </Tr> <Tr> <Td> LMC 175464 </Td> <Td> 1,200 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 135720 </Td> <Td> 1,200 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RAFGL 2139 </Td> <Td> 1,200 </Td> <Td> </Td> <Td> RAFGL 2139 is a rare red supergiant companion to WR 114 that has a bow shock . </Td> </Tr> <Tr> <Td> SMC 69886 </Td> <Td> 1,190 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> NML Cygni </Td> <Td> 1,183 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F05 </Td> <Td> 1,177 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> EV Carinae </Td> <Td> 1,168 - 2,880 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F03 </Td> <Td> 1,168 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 119219 </Td> <Td> 1,150 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F08 </Td> <Td> 1,146 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> BC Cygni </Td> <Td> 1,140 - 1,230 </Td> <Td> L / T </Td> <Td> Other recent estimates range from 856 R to 1,553 R . </Td> </Tr> <Tr> <Td> SMC 10889 </Td> <Td> 1,130 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> VX Sagittarii </Td> <Td> 1,120 - 1,550 </Td> <Td> L / T </Td> <Td> VX Sgr is a pulsating variable calculated to vary in size from 1,350 R to 1,940 R . </Td> </Tr> <Tr> <Td> LMC 141430 </Td> <Td> 1,110 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 175746 </Td> <Td> 1,100 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F13 </Td> <Td> 1,098 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RT Carinae </Td> <Td> 1,090 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F04 </Td> <Td> 1,082 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 174714 </Td> <Td> 1,080 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 68125 </Td> <Td> 1,080 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 49478 </Td> <Td> 1,080 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 20133 </Td> <Td> 1,080 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V396 Centauri </Td> <Td> 1,070 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 8930 </Td> <Td> 1,070 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Orbit of Jupiter </Td> <Td> 1,064--1,173 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> HV 11423 </Td> <Td> 1,060--1,220 </Td> <Td> L / T </Td> <Td> 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 . </Td> </Tr> <Tr> <Td> CK Carinae </Td> <Td> 1,060 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 25879 </Td> <Td> 1,060 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 142202 </Td> <Td> 1,050 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 146126 </Td> <Td> 1,050 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 67982 </Td> <Td> 1,040 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> U Lacertae </Td> <Td> 1,022 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F11 </Td> <Td> 1,015 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 143877 </Td> <Td> 1,010 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> KW Sagittarii </Td> <Td> 1,009 - 1,460 </Td> <Td> AD & L / T </Td> <Td> Margin of possible error: ± 142 solar radii (Torres 2013). </Td> </Tr> <Tr> <Td> SMC 46497 </Td> <Td> 990 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 140296 </Td> <Td> 990 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F09 </Td> <Td> 986 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> NR Vulpeculae </Td> <Td> 980 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 12322 </Td> <Td> 980 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 177997 </Td> <Td> 980 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 59803 </Td> <Td> 970 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> GCIRS 7 </Td> <Td> 960 ± 92 </Td> <Td> AD </Td> <Td> </Td> </Tr> <Tr> <Td> Betelgeuse (Alpha Orionis) </Td> <Td> 955 ± 217 </Td> <Td> AD </Td> <Td> Other recent estimates range from 887 ± 203 R to 1,180 R </Td> </Tr> <Tr> <Td> SMC 50840 </Td> <Td> 950 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F10 </Td> <Td> 931 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> S Cassiopeiae </Td> <Td> 930 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> IX Carinae </Td> <Td> 920 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> HV 2112 </Td> <Td> 916 </Td> <Td> L / T </Td> <Td> Most likely candidate for a Thorne - Zytkow Object . </Td> </Tr> <Tr> <Td> RSGC1 - F07 </Td> <Td> 910 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 54365 </Td> <Td> 900 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> NSV 25875 </Td> <Td> 891 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 109106 </Td> <Td> 890 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> RSGC1 - F06 </Td> <Td> 885 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 116895 </Td> <Td> 880 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 30616 </Td> <Td> 880 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 64048 </Td> <Td> 880 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V437 Scuti </Td> <Td> 874 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> V602 Carinae </Td> <Td> 860 - 1,050 </Td> <Td> L / T & AD </Td> <Td> Margin of possible error: ± 165 solar radii (Torres 2015). </Td> </Tr> <Tr> <Td> V669 Cassiopeiae </Td> <Td> 859 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 55681 </Td> <Td> 850 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 15510 </Td> <Td> 850 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 61753 </Td> <Td> 830 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 62090 </Td> <Td> 830 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 11709 </Td> <Td> 830 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V1185 Scorpii </Td> <Td> 830 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> Outer limits of the asteroid belt </Td> <Td> 816 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> LMC 142199 </Td> <Td> 810 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 134383 </Td> <Td> 800 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> BO Carinae </Td> <Td> 790 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 142907 </Td> <Td> 790 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SU Persei </Td> <Td> 780 </Td> <Td> L / T </Td> <Td> In the Perseus Double Cluster </Td> </Tr> <Tr> <Td> RS Persei </Td> <Td> 770 - 1,000 </Td> <Td> AD & L / T </Td> <Td> In the Perseus Double Cluster . Margin of possible error: ± 30 solar radii (Baron 2014). </Td> </Tr> <Tr> <Td> AV Persei </Td> <Td> 770 </Td> <Td> L / T </Td> <Td> In the Perseus Double Cluster </Td> </Tr> <Tr> <Td> V355 Cepheus </Td> <Td> 770 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> V915 Scorpii </Td> <Td> 760 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> S Cephei </Td> <Td> 760 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 11939 </Td> <Td> 750 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> HD 303250 </Td> <Td> 750 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V382 Carinae </Td> <Td> 747 </Td> <Td> </Td> <Td> The brightest yellow hypergiant in the night sky, one of the rarest types of star . Achmad (1992) calculates 600 R to 1,100 R or 700 ± 250 R . </Td> </Tr> <Tr> <Td> RU Virginis </Td> <Td> 742 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 137818 </Td> <Td> 740 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 48122 </Td> <Td> 740 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> SMC 56732 </Td> <Td> 730 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V648 Cassiopeiae </Td> <Td> 710 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> XX Persei </Td> <Td> 710 </Td> <Td> L / T </Td> <Td> Located in the Perseus Double Cluster and near the border with Andromeda . </Td> </Tr> <Tr> <Td> TV Geminorum </Td> <Td> 620 - 710 (--770) </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> HD 179821 </Td> <Td> 704 </Td> <Td> </Td> <Td> A yellow hypergiant, although most authors consider it as a supergiant, a protoplanetary nebula or a post-AGB star with a luminosity of only 16,000 L . </Td> </Tr> <Tr> <Td> LMC 169754 </Td> <Td> 700 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LMC 65558 </Td> <Td> 700 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> V528 Carinae </Td> <Td> 700 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Th_colspan="4"> The following well - known stars are listed for the purpose of comparison . </Th> </Tr> <Tr> <Td> V354 Cephei </Td> <Td> 690 - 1,520 </Td> <Td> L / T </Td> <Td> </Td> </Tr> <Tr> <Td> Antares A (Alpha Scorpii A) </Td> <Td> 680 </Td> <Td> AD </Td> <Td> This star appears to vary its size by 165 R . Older estimates have given radii over 800 R, but some are likely to have been affected by asymmetry of the atmosphere and the narrow range of infrared wavelengths observed . Other recent estimates range from 653 R to 1,246 R . </Td> </Tr> <Tr> <Td> CE Tauri </Td> <Td> 587--593 (--608) </Td> <Td> </Td> <Td> Second reddest star in the night sky . Can be occulted by the Moon, allowing accurate determination of its apparent diameter . </Td> </Tr> <Tr> <Td> R Leporis (Hind's "Crimson Star") </Td> <Td> 400--535 </Td> <Td> </Td> <Td> Margin of possible error: ± 90 solar radii . </Td> </Tr> <Tr> <Td> Rho Cassiopeiae </Td> <Td> 400 - 500 </Td> <Td> </Td> <Td> Yellow hypergiant, one of the rarest types of a star . </Td> </Tr> <Tr> <Td> Inner limits of the asteroid belt </Td> <Td> 412 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Mira A (Omicron Ceti) </Td> <Td> 332--402 </Td> <Td> </Td> <Td> Prototype Mira variable . De beck (2005) calculates 541 R . </Td> </Tr> <Tr> <Td> V509 Cassiopeiae </Td> <Td> 400--900 </Td> <Td> </Td> <Td> Yellow hypergiant, one of the rarest types of a star . </Td> </Tr> <Tr> <Td> CW Leonis </Td> <Td> 390--500, 700--826 </Td> <Td> L / T </Td> <Td> CW Leonis is one of the mistaken identities as the claimed planet "Nibiru" or "Planet X", due to its brightness as it approaches 1st magnitude . </Td> </Tr> <Tr> <Td> V838 Monocerotis </Td> <Td> 380 (in 2009) </Td> <Td> </Td> <Td> A short time after the outburst V838 Mon was measured at 1,570 ± 400 R . However the distance to this "L supergiant", 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 . </Td> </Tr> <Tr> <Td> S Doradus </Td> <Td> 100 - 380 </Td> <Td> </Td> <Td> Prototype S Doradus variable </Td> </Tr> <Tr> <Td> R Doradus </Td> <Td> 370 ± 50 </Td> <Td> </Td> <Td> Star with the second largest apparent size after the Sun . </Td> </Tr> <Tr> <Td> IRC + 10420 </Td> <Td> 357--1,342 </Td> <Td> L / T </Td> <Td> A yellow hypergiant that has increased its temperature into the LBV range . </Td> </Tr> <Tr> <Td> The Pistol Star </Td> <Td> 340 </Td> <Td> </Td> <Td> Blue hypergiant, among the most massive and luminous stars known . </Td> </Tr> <Tr> <Td> La Superba (Y Canum Venaticorum) </Td> <Td> 307 - 390 </Td> <Td> L / T </Td> <Td> Referred to as La Superba by Angelo Secchi . Currently one of the coolest and reddest stars . </Td> </Tr> <Tr> <Td> Solar System Habitable Zone </Td> <Td> 305 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Orbit of Mars </Td> <Td> 297--358 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Alpha Herculis (Ras Algethi) </Td> <Td> 284 ± 60 </Td> <Td> </Td> <Td> Moravveji et al also gives a range from 264 R to 303 R . At an estimated distance of 110 parsecs from the Sun, this corresponds to a radius of 400 ± 61 R . </Td> </Tr> <Tr> <Td> Sun's red giant phase </Td> <Td> 256 </Td> <Td> </Td> <Td> The core hydrogen would be exhausted in 5.4 billion years . In 7.647 billion years, The Sun would reach the tip of the red - giant branch of the Hertzsprung--Russell diagram . (see below) Reported for reference </Td> </Tr> <Tr> <Td> Eta Carinae A (Tseen She) </Td> <Td> 250, 60--800 </Td> <Td> </Td> <Td> Previously thought to be the most massive single star, but in 2005 it was realized to be a binary system . Other estimates gives 85 R to 195 R . </Td> </Tr> <Tr> <Td> Orbit of Earth </Td> <Td> 211--219 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Deneb (Alpha Cygni) </Td> <Td> 203 ± 17 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> LBV 1806 - 20 </Td> <Td> 200 </Td> <Td> </Td> <Td> Formerly a candidate for the most luminous star in the Milky Way . </Td> </Tr> <Tr> <Td> Orbit of Venus </Td> <Td> 154--157 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Epsilon Aurigae A (Almaaz) </Td> <Td> 143 - 358 </Td> <Td> </Td> <Td> ε Aur was incorrectly hailed as the largest star with a radius 2,000 R or 3,000 R, even though it later turned out not to be an infrared light star but rather a dusk torus surrounding the system . </Td> </Tr> <Tr> <Td> Peony Nebula Star </Td> <Td> 92 </Td> <Td> </Td> <Td> Candidate for most luminous star in the Milky Way . </Td> </Tr> <Tr> <Td> Rigel A (Beta Orionis A) </Td> <Td> 78.9--115 </Td> <Td> </Td> <Td> Margin of possible error: ± 7.4 solar radii . </Td> </Tr> <Tr> <Td> Canopus (Alpha Carinae) </Td> <Td> 71 ± 4 </Td> <Td> </Td> <Td> Second brightest star in the night sky . </Td> </Tr> <Tr> <Td> Orbit of Mercury </Td> <Td> 66--100 </Td> <Td> </Td> <Td> Reported for reference </Td> </Tr> <Tr> <Td> Aldebaran (Alpha Tauri) </Td> <Td> 44.13 ± 0.84 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Polaris (Alpha Ursae Minoris) </Td> <Td> 37.5 </Td> <Td> </Td> <Td> The current northern pole star . </Td> </Tr> <Tr> <Td> R136a1 </Td> <Td> 35.4 </Td> <Td> </Td> <Td> Also on record as the most massive and luminous star known . </Td> </Tr> <Tr> <Td> Arcturus (Alpha Boötis) </Td> <Td> 25.4 ± 0.2 </Td> <Td> </Td> <Td> Brightest star in the northern hemisphere . </Td> </Tr> <Tr> <Td> HDE 226868 </Td> <Td> 20 - 22 </Td> <Td> </Td> <Td> The supergiant companion of black hole Cygnus X-1 . The black hole is 500,000 times smaller than the star . </Td> </Tr> <Tr> <Td> VV Cephei B </Td> <Td> 13 - 25 </Td> <Td> </Td> <Td> The B - type main sequence companion of VV Cephei A . </Td> </Tr> <Tr> <Td> Sun's helium burning phase </Td> <Td> 10 </Td> <Td> </Td> <Td> After the red - giant branch the Sun has approximately 120 million years of active life left . Reported for reference </Td> </Tr> <Tr> <Td> Sun </Td> <Td> </Td> <Td> </Td> <Td> The largest object in the Solar System . Reported for reference </Td> </Tr> </Table> <Tr> <Th> Star name </Th> <Th> Solar radii (Sun = 1) </Th> <Th> Method </Th> <Th> Notes </Th> </Tr>

What is the biggest star in the sky