List of exoplanet extremes

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The following are lists of extremes among the known exoplanets. The properties listed here are those for which values are known reliably.

Extremes from Earth's viewpoint[edit]

Title Planet Star Data Notes
Closest rocky HD 219134 b[1][2] HR 8832 21.25 light years HD 219134 b is the size of 1.6 Earths and has a density of 6 g/cm3.[2]
Most distant OGLE-2005-BLG-390Lb[3] OGLE-2005-BLG-390L[3] 21,500 ± 3,300 light years An analysis of the lightcurve of the microlensing event PA-99-N2 suggests the presence of a planet orbiting a star in the Andromeda Galaxy (2.54 ± 0.11 Mly).[4]

A controversial microlensing event of lobe A of the double gravitationally lensed Q0957+561 suggests that there is a planet in the lensing galaxy lying at redshift 0.355 (3.7 Gly).[5][6]

Least distant Epsilon Eridani b Epsilon Eridani 10.475 light years
Star with the brightest apparent magnitude with a planet Pollux b Pollux[7] Apparent magnitude is 1.14 The evidence of planets around Vega with an apparent magnitude of 0.03 is strongly suggested by circumstellar disks surrounding it. Currently no planets have been confirmed yet.[8]
Largest angular distance separation from its host star GU Piscium b GU Piscium 42 arc seconds[9] WD 0806-661 b has an angular separation of 130.208333 arc seconds from WD 0806-661. However, its planetary origin is unknown.

Planetary characteristics[edit]

Title Planet Star Data Notes
Most massive DENIS-P J082303.1-491201 b[10] DENIS-P J082303.1-491201[11] 28.5±1.9 Jupiter masses[12] Most massive planet in the NASA Exoplanet Archive although, according to most definitions of planet, it may be too massive to be a planet, and may be a brown dwarf instead. It is part of an ultracool binary system.[10]
Least massive PSR B1257+12 A[13][14] PSR B1257+12[13][14] 0.02 MEarth[13][14] Mass of PSR B1257+12 A is based on an assumption of coplanarity with the outer two planets. The least massive exoplanet for which a true mass is known is Gliese 581 e with a mass of 2 MEarth.

Kepler-37b may be less massive (assuming Moon-like density), estimated mass >0.01 MEarth,[15] < 6 MEarth[16]

Biggest radius HAT-P-32b [17] HAT-P-32 2.04 Jupiter radii CT Chamaeleontis b is slightly larger at 2.2 Jupiter radii, but may be a brown dwarf star.
Smallest radius Kepler-37b Kepler-37 0.30 Earth radii Slightly larger than the Moon.
Most dense K2-22b K2-22 unknown g/cm3[note 1] With a mass of at most 445 MEarth and a radius of at most 2.5Earth the density is 0 to ~160  g/cm3.[19]
Least dense Kepler-453b [20] Kepler-453 0-0.7 g/cm3 [note 2] The density of Kepler-453b has not been accurately measured, and it has a Radius of 6.204 Re
Hottest Kepler-70b Kepler-70 7143 K[22]
Highest albedo Kepler-10b[citation needed] Kepler-10 0.5–0.6 (geometric albedo)
Lowest albedo TrES-2b GSC 03549-02811 Geometric albedo < 1%[23] Best-fit model for albedo gives even 0.04% (0.0004) [23]

Orbit characteristics[edit]

Title Planet Star Data Notes
Longest orbital period
(Longest year)
JMASS J2126-8140 TYC 9486-927-1 ~1,000,000 years
Shortest orbital period
(Shortest year)
Kepler-70b[24] Kepler-70[25] 0.24 days (5.8 hours)[24] Star is a post-red-giant with another close-period planet, Kepler-70c.[26]
Most eccentric orbit HD 20782 b[27] HD 20782[27] eccentricity of 0.97±0.01 HD 80606 b has an orbital eccentricity of 0.9349,[28] previously held record
Least eccentric orbit HD 209458 b HD 209458 eccentricity of 0.001 [citation needed]
Largest orbit around a single star[29][30] HD 106906 b[29] HD 106906[29] ~650 AU[29]
Smallest orbit Kepler-70b[24] Kepler-70 0.006 AU
Smallest orbit around binary star Kepler-47b Kepler-47AB ≃0.3 AU [31]
Smallest ratio of semi-major axis of a planet orbit to binary star orbit Kepler-16b Kepler-16AB 3.14 ± 0.01 [32]
Largest orbit around binary star DT Virginis c DT Virginis 1168 AU Star system is also known as Ross 458 AB. The planet was eventually confirmed to be below deuterium burning limit but its formation origin is unknown.
Largest orbit around a single star in a multiple star system Fomalhaut b Fomalhaut 115 AU The second stellar component of the system, TW Piscis Austrini, has a semi-major axis of 57,000 AU from Fomalhaut and the third stellar component, LP 876-10 orbits 158,000 AU away from Fomalhaut.
Largest distance between binary stars with a circumbinary planet FW Tauri AB b FW Tau AB ≈11 AU [citation needed]
Closest orbit between stars with a planet orbiting one of the stars OGLE-2013-BLG-0341LBb OGLE-2013-BLG-0341LB ~12-17 AU
(10 or 14 AU projected distance)[33]
OGLE-2013-BLG-0341L b's semi-major axis is 0.7 AU.[34]
Smallest semi-major axis difference between planets Kepler-70b and Kepler-70c[35] Kepler-70 0.0016 AU (about 240000 km) During closest approach, Kepler-70c would appear 5 times the size of the Moon in Kepler-70b's sky.
Smallest semi-major axis ratio between planets Kepler-36b and Kepler-36c Kepler-36 11% Kepler-36b and c have semi-major axes of 0.1153 AU and 0.1283 AU respectively, c is 11% further from star than b .

Stellar characteristics[edit]

Title Planet Star Data Notes
Highest metallicity HD 126614 Ab HD 126614 A +0.56 dex Located in a triple star system.
Lowest metallicity Kepler-271b,c Kepler-271 −0.951 dex BD+20°2457 may be the lowest metallicity planet host ([Fe/H]=−1.00), however the proposed planetary system is dynamically unstable. [2] The next lowest-metallicity system is Kepler-271. Planets were announced around even the extremely low metallicity stars HIP 13044 and HIP 11952, however these claims have since been disproven. [3]
Highest stellar mass HD 13189 b[36] HD 13189[36] 4.5±2.5 M[36] Margin of error means the star Epsilon Tauri with a stellar mass of 2.723 M is potentially the most massive known planet-harboring star.[37]
Lowest stellar mass 2M J044144 b[38] 2M J044144[38] 0.02 M[38]
Largest stellar radius HD 208527 b[39] HD 208527 51.1 (± 8.3) R Star is a red giant.
Smallest stellar radius (main sequence star) Kepler-42 b[40] Kepler-42 0.17 (± 0.05) R
Smallest stellar radius (brown dwarf) 2M 0746+20 b[41] 2M 0746+20 0.089 (± 0.003) R Planet's mass is very uncertain at 30.0 (± 25.0) Mjup.
Smallest stellar radius (pulsar) PSR J1719-1438 b[42] PSR J1719-1438 0.04 R
Oldest star HD 164922 b HD 164922[43] 13.4 billion years[43]
Hottest star with a planet NY Virginis b NY Virginis[44] 33247K This star is a subdwarf B star and has a red dwarf companion of 0.14 solar masses with a semi-major axis of slightly under 4 million kilometers from the primary component.
Hottest main-sequence star with a planet Fomalhaut b Fomalhaut[45] 8590K HIP 78530 has a surface temperature of 10500K, but it is uncertain whether the orbiting companion is a brown dwarf or planet.

System characteristics[edit]

Title System Planet(s) Star(s) Notes
System with most (confirmed) planets HD 10180 9 1 The planets are HD 10180b, c, ..., h. This system has 2 unconfirmed planets and more data is needed to confirm their existence.[46][47]
System with most stars Kepler 64 PH1b (Kepler 64b) 4 PH1 has a circumbinary orbit.

See also[edit]


  1. ^ NASA does not give a direct density value, however both mass and radius values are given. Using the PHL density Calculator the mass value of 445 Me and 2.5 Re were used and gave a result of 157.1 g/cm3 which was far higher than PSR J1719-1438 b's densities. However, since both these values are very much upper bound and the actual mass is likely dramatically lower, the density could be much lower or higher, as the mass is an absolute upper bound.[18]
  2. ^ NASA does not give a direct density value, however both mass and radius values are given. Using the PHL density Calculator mass value of 0-30 Me and 6.204 Re were used and gave a result of 0-0.7 g/cm which may or may not be lower than Kepler-51d's density depending on the radius of Kepler-52d and the mass of Kepler-453b. The volume of Kepler-51d may be an order of magnitude smaller, or somewhat larger, than that of Jupiter, with possible densities between 10 and about 500 grams per liter.[21]


  1. ^ "PIA19832: Location of Nearest Rocky Exoplanet Known". NASA. 30 July 2015. Retrieved 30 July 2015. 
  2. ^ a b Chou, Felicia; Clavin, Whitney (30 July 2015). "NASA's Spitzer Confirms Closest Rocky Exoplanet". NASA. Retrieved 31 July 2015. 
  3. ^ a b USA Today, "Smallest, most distant planet outside solar system found", Malcolm Ritter, 25 January 2006 (accessed 5 August 2010)
  4. ^ Schneider, J. "Notes for star PA-99-N2". The Extrasolar Planets Encyclopaedia. Retrieved 2010-08-06. 
  5. ^, "The Microlensing Event of Q0957+561" (accessed 5 August 2010)
  6. ^ Astrophysical Journal, "Microlensing Variability of the Gravitationally Lensed Quasar Q0957+561 A,B", R.E. Schild, June 1996, v.464, p.125, doi:10.1086/177304 , Bibcode1996ApJ...464..125S
  7. ^ Lee, T. A. (October 1970), "Photometry of high-luminosity M-type stars", Astrophysical Journal 162: 217, Bibcode:1970ApJ...162..217L, doi:10.1086/150648 
  8. ^ "NASA, ESA Telescopes Find Evidence for Asteroid Belt Around Vega" (Press release). Whitney Clavin, NASA. 8 January 2013. Retrieved 4 March 2013. 
  9. ^ "GU Psc b". The Extrasolar Planet Encyclopaedia. 
  10. ^ a b Sahlmann, J.; Lazorenko, P. F.; Ségransan, D.; Martín, E. L.; Queloz, D.; Mayor, M.; Udry, S. (August 2013). "Astrometric orbit of a low-mass companion to an ultracool dwarf". Harvard University. arXiv:1306.3225. Bibcode:2013A&A...556A.133S. doi:10.1051/0004-6361/201321871. 
  11. ^ Staff (8 March 2014). "DENIS-P J082303.1-491201". SIMBAD. Retrieved 8 March 2014. 
  12. ^ Staff. "DENIS-P J082303.1-491201 b". Caltech. Retrieved 8 March 2014. 
  13. ^ a b c New Scientist, "Smallest known exoplanet may actually be Earth-mass", Stephen Battersby, 19 January 2009 (accessed 5 August 2010)
  14. ^ a b c "Planets Around Pulsars", Alex Wolszczan (accessed 5 August 2010)
  15. ^ [NULL]. "Kepler: Discovery: Kepler-37b, a planet only slightly larger than the Moon". 
  16. ^; 2.78 ± 3.7 MEarth means 0 to 6 MEarth at 1 sigma
  17. ^ "HAT-P-32 b". The Extrasolar Planet Encyclopaedia. 
  18. ^ HEC, Calculator (22 October 2015). "Exoplanet Calculator". PHL. Retrieved 22 Oct 2015. 
  19. ^ "K2-22 b CONFIRMED PLANET OVERVIEW PAGE". NASA Exoplanet Archive. Retrieved 2015-10-14. 
  20. ^ "Kepler-453 b". 
  21. ^ HEC, Calculator (8 October 2015). "Exoplanet Calculator". PHL. Retrieved 8 Oct 2015. 
  22. ^ "HEC Top 10 Lists of Exoplanets". Retrieved 11 November 2014. 
  23. ^ a b David M. Kipping; et al. "Detection of visible light from the darkest world" (PDF). Monthly Notices of the Royal Astronomical Society. doi:10.1111/j.1745-3933.2011.01127.x. Retrieved 2011-08-12. 
  24. ^ a b c "Notes for Planet KOI-55 b". Extrasolar Planets Encyclopedia. Retrieved 1 January 2012. 
  25. ^ "Notes for star KOI-55". Extrasolar Planets Encyclopedia. Retrieved 1 January 2012. 
  26. ^ "Notes for Planet KOI-55 c". Extrasolar Planets Encyclopedia. Retrieved 1 January 2012. 
  27. ^ a b [1], (accessed 29 May 2014)
  28. ^ ScienceDaily, "Students Find Jupiter-Sized Oddball Planet", 22 April 2009 (accessed 5 August 2010)
  29. ^ a b c d Chow, Denise (December 6, 2013). "Giant Alien Planet Discovered in Most Distant Orbit Ever Seen". Retrieved December 8, 2013. 
  30. ^ Bailey, Vanessa; et al. (January 2014). "HD 106906 b: A planetary-mass companion outside a massive debris disk". The Astrophysical Journal Letters 780 (1). arXiv:1312.1265. Bibcode:2014ApJ...780L...4B. doi:10.1088/2041-8205/780/1/L4. L4. 
  31. ^ OROSZ J.; WELSH W.; CARTER J.; FABRYCKY D.; COCHRAN W.; et al. (2012). "Kepler-47: A Transiting Circumbinary Multi-Planet System". Science 337 (6101): 1511–4. Bibcode:2012Sci...337.1511O. doi:10.1126/science.1228380. PMID 22933522. 
  32. ^ Laurance R. Doyle; Joshua A. Carter; Daniel C. Fabrycky; Robert W. Slawson; Steve B. Howell; Joshua N. Winn; Jerome A. Orosz; Andrej Prsa; William F. Welsh; et al. (2011). "Kepler-16: A Transiting Circumbinary Planet". arXiv:1109.3432v1 [astro-ph.EP]. 
  33. ^; "(these projected separations are good proxies for the semi-major axis (afterupward adjustment by  \sqrt{3/2} to correct for projection effects)"
  34. ^ A. Gould. "A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary". 
  35. ^ J. H. Telting, S. Charpinet. "A compact system of small planets around a former red-giant star". Nature. Retrieved 23 April 2013. 
  36. ^ a b c "Notes for planet HD 13189 b". The Extrasolar Planets Encyclopaedia. Retrieved 2015-09-15. 
  37. ^ "Notes for planet eps Tau b". The Extrasolar Planets Encyclopaedia. Retrieved 2015-09-15. 
  38. ^ a b c Schneider, J. "Notes for planet 2M J044144 b". The Extrasolar Planets Encyclopaedia. Retrieved 2010-11-28. 
  39. ^ "HD 208527 b". The Extrasolar Planet Encyclopaedia. 
  40. ^ "Kepler-42 b". The Extrasolar Planet Encyclopaedia. 
  41. ^ "The Extrasolar Planet Encyclopaedia — 2M 0746+20 b". 
  42. ^ "PSR J1719-1438 b". 
  43. ^ a b "HD 164922 b". The Extrasolar Planets Encyclopaedia. Retrieved 2012-12-19. 
  44. ^ Joe Bauwens. "Sciency Thoughts: Planets in the NY Virginis system.". 
  45. ^ "Formalhaut b". The Extrasolar Planets Encyclopaedia. Retrieved 2013-03-30. 
  46. ^ "HD 10180 i". The Extrasolar Planets Encyclopaedia. Retrieved 2012-12-24. 
  47. ^ "HD 10180 j". The Extrasolar Planets Encyclopaedia. Retrieved 2012-12-24. 

External links[edit]