This is a list of stars which are the least voluminous known (the smallest stars by volume).
This is a list of small stars that are notable for characteristics that are not separately listed.
Star name | Star mean radius, kilometres | Star class | Notes | References | |
---|---|---|---|---|---|
CXOU J085201.4-461753 | 1.2 | Neutron star | [1] | ||
PSR B0943+10 | 2.6 | Pulsar (quark star?) | Neutron stars are stellar remnants produced when a star of around 8–9 solar masses or more explodes in a supernova at the end of its life. They are usually produced by stars of less than 20 solar masses, although a more massive star may produce a neutron star in certain cases. PSR B0943+10 is one of the least massive stars, with 0.02 solar masses. | [2] | |
CXO J232327.9+584842 | 2.7 | Neutron star | [1] | ||
RX J0720.4−3125 | 5 | ||||
PSR B1257+12 | 10 | Pulsar | Orbited by three planets. | [3] | |
PSR B0531+21 (Crab pulsar) | 10 | Relatively young at 999 years old as of June 2023. | [4] | ||
Geminga | 10 | [5] | |||
Vela pulsar | 10 | [6] | |||
XTE J1739-285 | 10.9 | Pulsar (quark star?) | [7] | ||
PSR J0348+0432 A | 13 ± 2 | Pulsar | Orbited by a white dwarf star (see below) | [8] | |
PSR J1748-2446ad | <16 | Fastest-spinning pulsar known. | [9] | ||
RX J1856.5−3754 | 19 | Neutron star | Closest neutron star discovered to date. | [10] | |
PSR B1620-26 A | 24 | Pulsar | An exoplanet orbits PSR B1620-26 A and its white dwarf companion (see below) in a circumbinary orbit. | ||
XTE J1650-500 B | 24 | Black hole | This binary X-ray transient system, XTE J1650-500, component black hole, at 3.8 solar masses, is smaller than the previous recordholder GRO J1655-40 B of 6.3 MSun in the microquasar system GRO J1655-40. | [11] | |
HD 49798 | 1,600 | White dwarf | One of the smallest white dwarf stars known. | [12] | |
ZTF J1901+1458 | 1,809 | Currently the most massive white dwarf known. | [13] | ||
GRW +70 8247 | 3,300 | [14] | |||
BPM 37093 | 3,965.5 | ||||
IK Pegasi B | 4,174 | The nearest supernova candidate. (Type Ia) | [15] | ||
Sirius B | 5,466 | Historically first detected white dwarf star | [16] | ||
LB 1497 | 5,494.5 | [17] | |||
40 Eridani B | 5,547.5 | ||||
U Geminorum white dwarf | 5,565 | [18] | |||
Gliese 915 | 6,748.3 | [19] | |||
AR Scorpii | 6,950 | The only known white dwarf pulsar | [20] | ||
LP 145-141 | 6,950 | 4th nearest white dwarf. [21] | |||
PSR B1620-26 B | 6,950 | An exoplanet orbits PSR B1620-26 B and its pulsar companion (see above) in a circumbinary orbit. | |||
G 29-38 | 6,950 | [22] | |||
Van Maanen 2 | 7,650 | 3rd nearest white dwarf. | [23] | ||
QS Virginis A | 7,658 | ||||
Stein 2051 B | 7,930 | [24] | |||
Ross 548 (ZZ Ceti) | 8,209 | [25] | |||
Procyon B | 8,595 | Second nearest white dwarf. | [26] | ||
GD 165 A | 8,626.5 | [25] | |||
ESO 439-26 | 8,775.5 | Faintest known white dwarf. [27] | |||
Wolf 489 | 9,044 | [28] | |||
HD 44120 C | 9,044 | [29] | |||
WD 1856+534 | 9,113.67 | [30] | |||
Epsilon Reticuli B | 9,185 | [31] | |||
RR Caeli white dwarf | 10,908.5 | [32] | |||
WD 1145+017 | 13,926.84 | Host star of one of the smallest exoplanets. | [33] | ||
NN Serpentis white dwarf | 14,679.5 | [34] | |||
Central star of the Dumbbell Nebula | 38,265 | [35] | |||
PSR J0348+0432 B | 45,268 | A white dwarf that orbits its pulsar companion (see above) | [8] | ||
WISE J1810–1010 | 46,840 | Brown dwarf | Smallest known brown dwarf. | [36] | |
EPIC 201702477 | 54,120 | [37] | |||
Epsilon Indi Ba | 55,656 | [38] | |||
LHS 6343 C | 55,978 | [39] | |||
Epsilon Indi Bb | 57,050 | [38] | |||
54 Piscium B | 57,050 | [40] | |||
2MASS J1126−5003 | 57,193.5 | [41] | |||
UGPS J0521+3640 | 57,193.5 | ||||
SSSPM J2356-3426 | 58,160 | Red dwarf | The smallest red dwarf. | [42] | |
EBLM J0555-57Ab | 60,000 | This red dwarf has a size comparable to that of the planet Saturn. As of 2019, it is the second lightest hydrogen-fusing star known, marginally heavier (0.0777-0.0852M☉) than the 2MASS J0523-1403. Although its mass is comparable to that of TRAPPIST-1, its radius is 1/3 smaller. | [43] [44] [45] | ||
Luhman 16 A | 60,768 | Brown dwarf | Luhman 16 A and Luhman 16 B are the closest brown dwarf stars to Earth, and the third-nearest star system to the Solar System. | [lower-alpha 1] | |
SSSPM J0829-1309 | 61,300 | Red dwarf | An L2 dwarf that is fusing hydrogen. Similarly to 2MASS J0523-1403, SSSPM J0829-1309 is one of the least luminous and massive hydrogen-fusing stars, and is smaller than Jupiter. | [46] [47] | |
WISE 1405+5534 | 61,483 | Brown dwarf | [48] | ||
2MASS 0939-2448 B | 62,600 | [49] | |||
UGPS 0722-05 | 63,340 | Possibly a rogue planet | [50] | ||
2MASS 0243−2453 | 64,000 | [51] | |||
2MASS J0348−6022 | 64,700 | [52] | |||
SDSS J1416+1348 A | 65,772.5 | [53] | |||
WISEPC J205628.90+145953.3 | 66,487.5 | [48] | |||
WISE 1738+2732 | 66,487.5 | [54] | |||
SCR 1845−6357 A | 66,790 | Red dwarf | |||
2MASS 0937+2931 | 67,200 | Brown dwarf | [55] | ||
SDSS J1416+1348 B | 67,200 | [56] | |||
DENIS J081730.0−615520 | 67,200 | [55] | |||
Kelu-1 B | 67,900 | ||||
Kelu-1 A | 68,180 | ||||
DENIS 0255−4700 | 69,600 | [57] | |||
R Aquarii B | 69,600 | White dwarf | Part of a symbiotic binary star system containing a red giant and a white dwarf. | [58] | |
HN Pegasi B | 70,265 | Brown dwarf | [59] | ||
2MASS J0523-1403 | 70,600 | Red dwarf | As in 2019, with mass 67.54±12.79MJ (0.0523-0.0767M☉) is the lowest known mass hydrogen-burning star. | [60] [46] [55] | |
GD 165 B | 71,492 | Brown dwarf | [61] | ||
DENIS-P J1058.7−1548 | 71,492 | [62] | |||
LHS 2924 | 71,657 | Red dwarf | [63] | ||
2MASS 0036+1821 | 72,200 | Brown dwarf | [55] | ||
Luhman 16 B | 74,350 | Luhman 16 B and Luhman 16 A are the closest brown dwarf stars to Earth, and the third-nearest star system to the Solar System. | [lower-alpha 1] | ||
Teegarden's Star | 74,439.9 | Red dwarf | Has two potentially habitable planets | [42] | |
DENIS J1048−3956 | 75,135.5 | [64] | |||
DX Cancri | 76,527 | [65] | |||
LHS 292 | 76,527 | [66] | |||
TVLM 513-46546 | 76,527 | Has one confirmed exoplanet | |||
Gliese 229 B | 79,000 | Brown dwarf | |||
OGLE-TR-122B | 81,100 | Red dwarf | This was once the smallest known actively fusing star, when found in 2005, through 2013. It is the smallest eclipsing red dwarf, and smallest observationally measured diameter. | [67] [68] [69] | |
CoRoT-15b | 82,200 | Brown dwarf | [70] | ||
VB 10 | 82,300 | Red dwarf | [71] | ||
TRAPPIST-1 | 82,925 | Hosts a planetary system with at least seven rocky planets. | [72] | ||
LHS 2090 | 83,500 | [73] | |||
VB 8 | 84,450 | [71] | |||
2MASS 0939-2448 A | 87,220 | Brown dwarf | [74] | ||
Gliese 412 B | 90,400 | Red dwarf | [75] | ||
Gliese 1002 | 95,310 | Has two confirmed exoplanets | [76] | ||
Wolf 359 | 100,180.8 | [71] | |||
NN Serpentis red dwarf | 103,660 | [77] | |||
NY Virginis A | 105,050 | B-type subdwarf | [78] | ||
Gliese 1061 | 105,746.4 | Red dwarf | Has three confirmed exoplanets, two of them are in the habitable zone. | [71] | |
LP 890-9 | 106,580 | Has two confirmed exoplanets, one of them (LP 890-9c) is in the habitable zone. | [79] | ||
Proxima Centauri | 107,277 | This is the nearest neighbouring star to the Sun. | [80] | ||
Luyten 726-8 B (UV Ceti) | 110,615 | The archetypal type of the flare stars. | [81] | ||
NY Virginis B | 111,300 | [82] | |||
TZ Arietis | 112,000 | Has one confirmed exoplanet | [83] | ||
Luyten 726-8 A (BL Ceti) | 114,790 | [81] | |||
YZ Ceti | 116,877.5 | Has three confirmed exoplanets | [84] | ||
UY Sextantis | 118,250 | B-type subdwarf | [85] | ||
Kepler-42 | 121,750 | Red dwarf | Has three confirmed exoplanets | [86] | |
EZ Aquarii A (Luyten 789-6 A) | 121,750 | [87] | |||
HW Virginis B | 121,835 | [88] | |||
Gliese 1151 | 123,900 | Has one confirmed exoplanet | [89] | ||
Groombridge 34 B | 125,200 | [90] | |||
Wolf 1069 | 126,130 | Has one confirmed potentially habitable exoplanet | [91] | ||
HW Virginis A | 127,404.6 | B-type subdwarf | [88] | ||
Gliese 3323 | 129,539.5 | Red dwarf | Has two confirmed exoplanets | [42] | |
Barnard's Star | 130,100 | The star with the highest proper motion, [92] and the second-nearest star system to the Solar system. | [93] | ||
Ross 248 | 132,183 | [75] | |||
Alpha Mensae B | 132,200 | [94] | |||
Ross 128 | 136,844 | Has one confirmed exoplanet | [95] | ||
LTT 1445 C | 137,050 | [96] | |||
Kepler-70 | 141,225 | B-type subdwarf | Has two unconfirmed exoplanets, which may be the hottest exoplanets known. | [97] | |
RR Caeli red dwarf | 141,225 | Red dwarf | |||
Gliese 1214 | 141,922 | Has a confirmed exoplanet | [71] | ||
Gliese 754 | 142,618.5 | [98] | |||
LHS 1140 | 142,618.5 | Has two confirmed exoplanets | [71] | ||
EZ Aquarii B (Luyten 789-6 B) | 146,100 | [99] | |||
Gliese 1132 | 149,575 | Has two confirmed exoplanets | [71] | ||
LSR J1835+3259 | 150,133 | Brown dwarf | [100] | ||
CT Chamaeleontis B | 157,282.4 | ||||
Kepler-1649 | 161,400 | Red dwarf | Has two confirmed exoplanets | [101] | |
LTT 1445 B | 164,185 | [96] | |||
CM Draconis B | 166,689.72 | [102] | |||
Ross 695 | 167,000 | [103] | |||
Ross 154 | 167,000 | [104] | |||
Kruger 60 B | 167,000 | [105] | |||
2M1207 A | 173,925 | Brown dwarf | Has one confirmed exoplanet | [106] | |
CM Draconis A | 176,000 | Red dwarf | [107] | ||
AM Herculis red dwarf | 180,882 | [108] | |||
Z Andromedae B | 184,530.63 | White dwarf | Largest known white dwarf. Part of a symbiotic binary star system containing a red giant and a white dwarf. | [109] | |
55 Cancri B | 186,447.5 | Red dwarf | [110] | ||
LTT 1445 A | 188,500 | Has three confirmed exoplanets, one of them is in the habitable zone | [111] | ||
Struve 2398 B | 189,925 | [75] | |||
Gliese 105 B | 193,405 | [75] | |||
LHS 475 | 194,030.5 | Has one confirmed exoplanet | [112] | ||
HR 7703 B | 194,800 | [105] | |||
Mu Cassiopeiae Ab | 201,750 | [113] | |||
Kapteyn's Star | 202,448.7 | This is the closest halo star to the Sun. | [114] | ||
Stein 2051 A | 203,150 | [115] | |||
Gliese 581 | 215,650 | Has three confirmed exoplanets | [71] | ||
40 Eridani C | 215,650 | [116] | |||
Wolf 1061 | 221,900 | Has three confirmed exoplanets | [71] | ||
Xi Ursae Majoris Ab | 222,600 | [117] | |||
YZ Canis Minoris | 225,400 | [83] | |||
Wolf 437 (Gar) | 228,190 | Has one confirmed exoplanet | [118] | ||
Gliese 1 | 229,580 | [119] | |||
Gliese 667 C | 234,450.9 | Has two confirmed exoplanets | [71] | ||
Luyten's Star | 243,500 | Has two confirmed exoplanets and other two unconfirmed | [120] | ||
Kruger 60 A | 243,500 | [105] | |||
Struve 2398 A | 246,300 | [71] | |||
EV Lacertae | 250,500 | [121] | |||
Theta Cygni B | 250,500 | [122] | |||
Gliese 251 | 253,235 | Has one confirmed exoplanet | [123] | ||
AT Microscopii B | 257,400 | [124] | |||
Regulus C | 257,400 | [125] | |||
Gliese 876 | 258,800 | Has four confirmed exoplanets | [71] | ||
LHS 6343 A | 259,495 | [39] | |||
Gliese 412 A | 264,400 | [75] | |||
Groombridge 34 A | 267,800 | [71] | |||
L 34-26 | 270,000 | It hosts the exoplanet with the longest known orbital period, COCONUTS-2b, which takes about 1.1 million years to complete an orbit around its star. | [127] | ||
Teide 1 | 270,240 | Brown dwarf | [128] [129] | ||
AD Leonis | 271,323 | Red dwarf | [130] | ||
Gliese 908 | 271,323 | [103] | |||
HIP 79431 (Sharjah) | 272,000 | Has one confirmed exoplanet | [131] | ||
Lalande 21185 | 273,500 | [132] | |||
LHS 6343 B | 274,100 | [39] | |||
Gliese 179 | 278,300 | Has two confirmed exoplanets | [42] | ||
KOI-4777 | 278,300 | Has one confirmed exoplanet | [133] | ||
Gliese 163 | 284,550 | Has five confirmed exoplanets | [71] | ||
AT Microscopii A | 285,250 | [124] | |||
Gliese 588 | 292,200 | [134] | |||
Gliese 686 | 292,200 | Has a confirmed exoplanet | [135] | ||
TOI 700 | 292,200 | Has four confirmed exoplanets | [136] | ||
QS Virginis B | 292,404 | ||||
Gliese 180 | 294,211.5 | Has two confirmed exoplanets | [42] | ||
Gliese 408 | 299,150 | [105] | |||
Gliese 3634 | 299,150 | Has a confirmed exoplanet | [137] | ||
U Geminorum red dwarf | 299,150 | [18] | |||
Gliese 436 | 300,542 | Has a confirmed exoplanet | [71] | ||
Sigma Coronae Borealis C | 304,000 | [138] | |||
WR 93b | 306,108 | Wolf-Rayet | [139] | ||
Gliese 832 | 307,500 | Red dwarf | Has two exoplanets | [71] | |
Gliese 877 | 307,500 | [140] | |||
Tabby's Star B | 313,065 | [141] | |||
Gliese 521 | 327,000 | [142] | |||
Lacaille 9352 | 329,750 | Has two confirmed exoplanets and one unconfirmed | [71] | ||
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. | [43] [44] [45] |
Brown dwarf | WISEA 1810−1010 | 0.067 | 0.655 | 7.29 | 46,840 km (29,110 mi) | 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. | [36] | |
White dwarf | HD 49798 | 0.0023 | 0.023 | 0.25 | 1,600 km (990 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. | [12] |
Neutron star | CXOU J085201.4-461753 | 0.0000017 | 0.000017 | 0.00019 | 1.2 km (0.75 mi) | 1968 | 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. | |
Stellar-mass black hole | XTE J1650-500 B | 0.0000344828 | 0.000335702 | 0.00376285 | 24 km (15 mi) | 2008 | Black holes are stellar remnants usually produced when extremely massive stars explode in a supernova or hypernova at the end of their lives. | [11] |
Red dwarfs are considered the smallest star known that are active fusion stars, and are the smallest stars possible that is not a brown dwarf.
Star name | Date | Radius Solar radii (Sun = 1) | Radius Jupiter radii (Jupiter = 1) | Radius km (mi) | Notes | |
---|---|---|---|---|---|---|
SSSPM J2356-3426 | 2020-Today | 0.0836 | 0.832 | 58,161 kilometres (36,140 mi) | ||
EBLM J0555-57Ab | 2017-2020 | 0.084 | 0.84 | 60,000 km (37,000 mi) | This star has a size comparable to that of Saturn. | [43] [44] [45] |
2MASS J0523-1403 | 2013-2017 | 0.102 | 1.01 | 70,600 km (43,900 mi) | Lowest mass main sequence star as in 2020. | [60] [46] [143] [55] |
OGLE-TR-122B | 2005-2013 | 0.117 | 1.16 | 81,100 km (50,400 mi) | [67] [68] [69] | |
HD 63454, formally named Ceibo, is a star located in the southern circumpolar constellation Chamaeleon near the border with Mensa To see the star, one needs a small telescope because it has an apparent magnitude of 9.36, which is below the limit for naked eye visibility. The object is located relatively close at a distance of 123 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 33.8 km/s. At its current distance, HD 63454's brightness is diminished by two tenths of a magnitude due to interstellar dust. It has an absolute magnitude of +6.68.
HD 20782 is the primary of a wide binary system located in the southern constellation Fornax. It has an apparent magnitude of 7.38, making it readily visible in binoculars but not to the naked eye. The system is located relatively close at a distance of 117 light-years based on Gaia DR3 parallax measurements, but it is receding with a heliocentric radial velocity of 40.7 km/s. At its current distance, HD 20782's brightness is diminished by 0.12 magnitudes due to interstellar extinction and it has an absolute magnitude of +4.61.
2MASS J03552337+1133437 is a nearby brown dwarf of spectral type L5γ, located in constellation Taurus at approximately 29.8 light-years from Earth.
HD 46588 is a star in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.44, allowing it to be faintly seen with the naked eye. The object is relatively close at a distance of only 59 light years but is receding with a heliocentric radial velocity of 15 km/s.
HD 194012 is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.15, making it visible to the naked eye under ideal conditions. The star is relatively close at a distance of only 85 light years but is receding with a heliocentric radial velocity of 4.5 km/s.
HR 8526, also known as HD 212168, is the primary of a triple star located in the southern circumpolar constellation Octans. The star and its companion have apparent magnitudes of 6.12 and 9.36 respectively. The system is located relatively close at a distance of 76 light years based on Gaia DR3 parallax measurements, but is receding with a heliocentric radial velocity of 15 km/s.
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