List of exoplanet extremes

The study of exoplanets is one of the most dynamic emerging fields of science, thus these values may change as new discoveries are made.

[13][14][15][16] An Earth-mass planet claimed to orbit Alpha Centauri B (apparent magnitude = 1.33) was subsequently refuted.

[18] This star was previously thought to harbour a directly-imaged planet named Fomalhaut b, before the realization of object as an expanding debris cloud from a planetesimal collision.

[41] A predicted highly evaporating planet was proposed to orbit the star FU Orionis north with a density of about 0.0042 g/cm3.

[d] A candidate planet was suggested to orbit the central star of the Helix Nebula with an equilibrium temperature of 4,970 K.[48] Kepler-70b and Kepler-70c are often described as the hottest known exoplanets, both at >6800 K (assuming an albedo of 0.1 for both),[49] but their existence are highly doubtful.

2MASS J04414489+2301513 b is listed as the youngest planet in the NASA Exoplanet Archive, at an age of 1 Myr,[1] but fails the mass ratio criterion of the IAU working definition of an exoplanet; the mass ratio with the primary is larger than the L4/L5 limit of stability ≈ 1/25[62] and the companion is 'more likely to have been produced by cloud core fragmentation' (similar to a star).

[64] CI Tauri c would be the youngest radial velocity planet at an age of 2–3 Myr, if confirmed.

[70] A brown dwarf or planetary-mass companion was announced around the population II star HE 1523-0901, whose metallicity is −2.65±0.22 dex.

[73] A disputed substellar companion, possibly a Jovian planet, was announced to orbit[104] the B-type subdwarf star HD 149382 with a metallicity of -1.30 dex.

[83] Candidate planets were reported around the red giants V Camelopardalis (716±185 R☉),[111][112] R Fornacis (585 R☉[i]),[113][114] V Hydrae (430 R☉),[115] R Leonis (320-350 R☉)[111][116] and L2 Puppis (123±14 R☉).

The stars R126, R66 and HH 1177 in the Large Magellanic Cloud have luminosities of 1400000 L☉, 320000 L☉ and 19000 L☉[117][109] and have dust discs but no planets have been detected yet.

[114][111] A gas giant planet was found orbiting TVLM 513-46546,[139] which is an ultracool star (2242 K) located close to the brown dwarf/red dwarf mass boundary.

30 Arietis Bb was believed to be either brown dwarf or a massive gas giant in a quadruple star system before later studies revealing a true mass well above the red dwarf-mass limit of 80 MJup.

[148] The quintuple and quadruple star systems GG Tauri and HD 98800 both have several protoplanetary disks but no planets have been detected yet.