Below is a list of the largest exoplanets so far discovered, in terms of physical size, ordered by radius.
This list of extrasolar objects may and will change over time because of inconsistency between journals, different methods used to examine these objects and the already extremely hard task of discovering exoplanets, or any other extrasolar objects for that matter. These objects are not stars, and are quite small on a universal or even stellar scale. Then there is the fact that these objects might be brown dwarfs, sub-brown dwarfs, or not exist at all. Because of this, this list only cites the most certain measurements to date and is prone to change.
The sizes are listed in units of Jupiter radii (71 492 km). This list is designed to include all planets that are larger than 1.7 times the size of the largest planet in the Solar System, Jupiter. Some planets that are smaller than have been included for the sake of comparison.
| Illustration | Exoplanet name | Radius | Key | Notes |
|---|---|---|---|---|
| Sun (Sol) | (695 700 km) | The only star in the solar system where Earth orbits around. Reported for reference. | ||
| Size limit for brown dwarfs | 8[1] | |||
| Proplyd 133-353 | | A candidate rogue planet/sub-brown dwarf with a photoevaporating disk. It is located in the Orion Nebula Cluster. At an age younger than 500,000 years it is one of the youngest free-floating planetary-mass object candidates known. More information about Proplyd 133-353 and estimates of its radius are available below: | ||
| V2384 Orionis A (2M0535-05 A) | [2] | Eclipsing binary brown dwarf primary component, ~1 million years old, ~ dynamical mass estimate Reported for reference. | ||
| V2384 Orionis B (2M0535-05 B) | | Eclipsing binary brown dwarf secondary component, ~1 million years old, ~ dynamical mass estimate Reported for reference. | ||
| KPNO-Tau-4 | 4.1[3] [4] | |||
| GQ Lupi b (GQ Lup b) | GQ Lupi b has a mass of 1 – ; in the higher half of this range, it may be classified as a young brown dwarf. GQ Lup Ab / GQ Lup b / GQ Lup B should not be confused with the stellar mass companion GQ Lup C at about 2400 AU separation. Most recently . | |||
| HD 100546 b (KR Muscae b) | 3.4 | Initially reported due to the diffuse dust and gas envelope or debris disk surrounding the planet, making the planet candidate the largest exoplanet discovered by size, a 2017 study calculated HD 100546 b as a very highly reddened substellar object with a good-fit effective temperature of and a mass and radius of and, making it still one of the largest exoplanet candidates discovered by size. | ||
| OTS 44 | 3.23.6[7] | Very likely a brown dwarf or sub-brown dwarf. It is surrounded by a circumstellar disk of dust and particles of rock and ice. The currently preferred radius estimate is done by SED modelling including substellar object and disk model. | ||
| 2M J044144 b (2MASS J0441+2301 Bb) | 3.06[8] |
| ||
| Kapteyn's Star | 2.832 ± 0.243[10] | The closest halo star / red subdwarf to the Solar System at the distance of . Also having the second-highest proper motion of any stars. Having an age of 11.5 Gyr. Reported for reference. | ||
| DH Tauri b (DH Tau b) |
| ← | , 14.2,[11],[12] . DH Tau b has itself a companion candidate, an exomoon candidate of about, referred to as DH Tau Bb. Its estimated orbital period is about 320 years.[13] | |
| SR 12 (AB) c | 2.38 [14] | ← | 14,[15] 1215,[16], is at the very edge of the deuterium burning limit. | |
| TWA 29 | 2.222 [17] | 6.6 | ||
| Hot Jupiter limit | 2.2 | Theoretical limit for hot Jupiters close to a star, that are limited by tidal heating, resulting in 'runaway inflation' | ||
| CT Chamaeleontis b (CT Cha b) | 2.2[18] |
| ||
| ROXs 42B b |
| ← | 9 ;[20] ;[21] 3.2 – 27 ; | |
| PDS 70 b | 2.092.72 | ← | Mass estimated at 3.2, 7.9, < 10 (2 σ), <~ 15 (total)[22] | |
| HAT-P-67b | 2.085[23] | ← | 0.34 ; a very puffy Hot Jupiter. Currently the largest known planet with an accurately and precisely measured radius.[24] | |
| XO-6b | 2.07 | ← | 4.4 ; a very puffy Hot Jupiter | |
| Cha 110913-773444 | 2.02.1 | A rogue planet (Likely a sub-brown dwarf) that is surrounded by a protoplanetary disk. It is one of youngest free-floating substellar objects with 0.5–10 Myr. The currently preferred radius estimate is done by SED modelling including substellar object and disk model. | ||
| 2.00 ; 3[25] [26] | ||||
| Ditsö̀ (WASP-17b) | 1.991[27] | ← | 0.486 ; has an extremely low density of 0.08 g/cm3.[28] Possibly largest exoplanet at the time of discovery.[29] | |
| Kepler-435b | 1.99[30] | ← | ||
| , 2.037 | ← | 0.941 ; a very puffy Hot Jupiter. Other estimates give 1.789 .[31] | ||
| CFHTWIR-Oph 98 a | 1.95 ; 2.14[32] | Either a brown dwarf or sub-brown dwarf with a sub-brown dwarf/planet companion CFHTWIR-Oph 98 b. | ||
| WASP-12b | 1.937[33] | ← | This planet is so close to its parent star that its tidal forces are distorting it into an egg-like shape. As of September 2017, it has been described as "black as asphalt", and as a "pitch black" hot Jupiter as it absorbs 94% of the starlight that reaches its surface. WASP-12b is suspected to have one exomoon due to a curve of change of shine of the planet observed regular variation of light.[34] | |
| BD-14 3065 b | ← | |||
| KELT-19 Ab | [35] | ← | ||
| Dimidium (51 Pegasi b) | 1.9[36] | ← | First exoplanet to be discovered orbiting a main-sequence star. Prototype hot Jupiter. | |
| 1.891[37] | ← | Hottest confirmed exoplanet known, with a temperature of K. | ||
| 1.89[38] | ← | |||
| TOI-1518 b | ← | |||
| HAT-P-70b | ← | |||
| Tylos (WASP-121b) | 1.865[39] | ← |
| |
| HATS-23b | 1.86[40] | ← | ||
| CFHTWIR-Oph 98 b | [41] | May be a sub-brown dwarf. | ||
| KELT-8b | 1.86[42] | ← | ||
| KPNO-Tau-12 | 1.84; 2.22 | |||
| 1.83[43] | ← | The tidally-locked planet where winds move 18,000 km/h, and where molten iron rains from the sky due to daytime temperatures exceeding 2400C.[44] [45] WASP-76b is suspected to have an exo-Io candidate due to the sodium being detected via absorption spectroscopy around WASP-76b.[46] | ||
| 1.827,[47] | ← | |||
| TYC 8998-760-1 b | [48] 3.0, | Directly imaged companion around TYC 8998-760-1, an analog to the Sun, expect in age. TYC 8998-760-1 has an age of 27 myr. Its largest orbital body (TYC 8998-760-1 b) is 22 ± 3 ; likely making it a brown dwarf.[49] [50] [51] | ||
| Barnard's Star (Proxima Ophiuchi) | 1.820 ± 0.010[52] | Second nearest stellar system to the Sun at the distance of and closest star in the northern celestial hemisphere. Also having the highest proper motion of any stars. Having an age of likely more than twice the age of the Solar System. Reported for reference. | ||
| WASP-178b | ← | |||
| Saffar (Upsilon Andromedae b) | 1.8[53] | ← | ; Saffar orbits very close to its host star of 0.0595 AU, completing an orbit in 4.617 days.[54] | |
| TrES-4b | 1.799[55] | ← | This planet has a density of 0.2 g/cm3, about that of balsa wood, less than Saturn's 0.7 g/cm3. | |
| WASP-122b | 1.792 | ← | ||
| KELT-12b | 1.78[56] | ← | ||
| TOI-640 b | ← | |||
| TOI-2193 Ab | 1.77[57] | ← | ||
| TOI-2669b | 1.76[58] | ← | ||
| HATS-26b | 1.75[59] | ← | ||
| KELT-14b | 1.743 | ← | ||
| KELT-15b | ← | |||
| HAT-P-57b | ← | |||
| KELT-20b (MASCARA-2b) | 1.735,[60] | ← | An ultra-hot Jupiter with the mass less than . | |
| HAT-P-64b | ← | |||
| 1.70, | ← |
| ||
| Pollera (WASP-79b) | 1.702.09 | ← | A hot Jupiter, with the mass,,[61] less than that of Jupiter. In 2019 and 2020, the transmission spectra of WASP-79b were taken utilizing HST and Spitzer Space Telescope, with best fit being the hazy atmosphere containing about 1% water and traces of Iron(I) hydride. The presence of iron hydride was confirmed in 2021, along with tentative detection of vanadium oxide. Also, in 2022 an atmospheric sodium has been detected. | |
| Qatar-7b | ← | |||
| A few examples with radii under 1.7 . | ||||
| , 1.706[62] | ← | |||
| Kepler-12b | 1.695,[63] | ← | ||
| 1RXS 1609b | 1.664[64] | 14 ; is likely a brown dwarf. It's the third exoplanet to be announced as directly imaged orbiting a sun-like star (after GQ Lup b and AB Pic b). | ||
| AB Aurigae b | 1.62.75 | The large radius of 2.75 is only valid for 1 Myr. Several publications give a higher age, e.g. 1-5 Myr, Myr,[65] 6.0 Myr.[66] Its optical/UV detection is disputed, its accretion rate is disputed[67] , while its existence as a planet after original detection in the IR needs confirmation. | ||
| AB Pictoris b | ← | Previously believed to be a likely brown dwarf, with mass estimates of 13−[68] to,[69] its mass is now estimated to be, with an age of 13 million years. | ||
| KOI-13b (Kepler-13 Ab) | , 2.216[70] | ← | Esteves et al. gives also radii of and . Batalha et al. calculate .[71] | |
| Proxima Centauri (Alpha Centauri C) | [72] | The nearest star to the Sun at the distance of, orbiting around the Alpha Centauri AB system, the nearest star system to the Sun, at a separation of,[73] equivalent to about 430 times the radius of Neptune's orbit. Reported for reference. | ||
| Kepler-7b | 1.478[74] | ← | ||
| Beta Pictoris b | 1.46[75] | ← | The companion orbits close to the plane of the debris disk with a low eccentricity and a period of 20–21 years. It will soon have good coverage across its full orbit and is followed with the radial velocity method, allowing to derive increasingly precise mass measurements. | |
| , 1.7[76] | ← | |||
| PSO J318.5−22 | 1.38[77] | An extrasolar object that does not seem to be orbiting any star, see: rogue planet. | ||
| 1.359[78] | ← | First known transiting exoplanet. | ||
| HR 8799 c | 1.3[79] | ← | Second outermost planet discovered using the direct imaging technique in the HR 8799 system. This planet contains water and carbon monoxide in its atmosphere. | |
| TrES-2b (Kepler-1b) | [80] | ← | Darkest known exoplanet due to an extremely low geometric albedo. It absorbs 99% of light. | |
| HR 8799 d | 1.2 | ← | Upon initial discovery, it was the innermost known planet in the HR 8799 system. After the discovery of HR 8799 e in 2010, it is the second innermost planet known in the system. | |
| HR 8799 b | 1.2 | ← | Outermost planet discovered using the direct imaging technique in the HR 8799 system. | |
| HR 8799 e | 1.17[81] | ← | Fourth and innermost planet discovered using the direct imaging technique in the HR 8799 system. | |
| 2M1207b | 1.13[82] | First directly imaged exoplanet to have spectrum taken; although it may be a sub-brown dwarf / captured rogue planet, its mass of is well below the calculated limit for deuterium fusion in brown dwarfs of . | ||
| PDS 70 c | 1.13 | ← | ||
| CoRoT-3b | [83] | The issue of whether CoRoT-3b, with the mass of, is a planet or a brown dwarf depends on the definition chosen for these terms. According to one definition, a brown dwarf is an object capable of fusing deuterium, a process which occurs in objects more massive than . According to this definition, which is the one adopted by the International Astronomical Union's Working Group on Extrasolar Planets, CoRoT-3b is a brown dwarf.[84] However, some models of planet formation predict that planets with masses up to 25–30 Jupiter masses can form via core accretion.[85] If this formation-based distinction between brown dwarfs and planets is used, the status of CoRoT-3b becomes less clear as the method of formation for this object is not known. The issue is clouded further by the orbital properties of the object: brown dwarfs located close to their stars are rare (a phenomenon known as the brown-dwarf desert), while the majority of the known massive close-in planets (for example XO-3b, HAT-P-2b and WASP-14b) are in highly eccentric orbits, in contrast to the circular orbit of CoRoT-3b. | ||
| Epsilon Indi Ab | 1.08[86] | ← | Nearest extrasolar planet directly imaged. | |
| Kepler-39b (formerly KOI-423b) | 18.00 ; may be brown dwarf based on mass. | |||
| Jupiter | 1 (71 492 km) | Largest planet in the Solar System[87] Reported for reference. | ||