Many exoplanets have now been identified, and astronomers have been able to identify molecules in some of their atmospheres. In addition to the discovery citation and any molecular detections, you may view various sources of information about each exoplanet by clicking on the various icons:

Wikipedia entry (or the closest entry available)
The Extrasolar Planet Encylopedia (EPE) (an excellent technical resource cataloging nearly 5700 exoplanets as of May 2024)
NASA Exoplanet Catalog (a more general interest catalog)
ExoClock (monitoring the motion of transiting exoplanets)
exokyoto (Japanese language resource)

NOTES: Specifically tentative detections are indicated with italics or a question mark. disp = disputed detection; conf = confirmed detection; nd = non-detection.

ABOUT σ VALUES: Exoplanet molecule detections often have a σ value assigned to them, which is a measure of the "statistical significance" of the detection. A higher number indicates a detection that is stronger and less likely to be due to scatter or noise in the associated measurements. A value of 4-5σ is considered to be something of a threshold for a good detection. See this article for a helpful discussion of σ, with caveats about possible issues with assigned σ values. (2 July 2024)


EXOPLANET MOLECULES
DISCOVERY CITATION
2M0437b (super Jupiter)
Gaidos+(2023): CO, H2O, CH4
Zodiacal exoplanets in time (ZEIT) XII: a directly imaged planetary-mass companion to a young Taurus M dwarf star
E. Gaidos+. MNRAS 512:583-601 (2022).
CI Tau b
Flagg+(2019): CO
A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau
C. M. Johns-Krull+. ApJ 826:206 (2016).
GJ 1132 b (super Earth)
Swain+(2021): HCN, CH4, C2H2(nd), CO2(nd)
Mugnai+(2021): no molecules detected
A rocky planet transiting a nearby low-mass star
Z. K. Berta-Thompson+. Nature 527:204 (2015).
GJ 3470b (hot sub-Neptune
Benneke+(2019): H2O(>5σ), CH4(nd,<3σ)
Beatty+(2024): H2O(6.3σ), CO2O(7.3σ), CH4(3.8σ), SO2(4.0σ)
A hot Uranus transiting the nearby M dwarf GJ 3470. Detected with HARPS velocimetry. Captured in transit with TRAPPIST photometry
Bonfils+. A&A 546:A27 (2012).
GJ 9827 d (mini-Neptune)
Roy+(2023): H2O(3.39σ)
Piaulet-Ghorayeb+(2024): H2O
A System of Three Super Earths Transiting the Late K-Dwarf GJ 9827 at 30 pc
J. E. Rodriguez+. AJ 155:72 (2018).
HAT-P-11b (hot Neptune)
Frain+(2014): H2O(5.1σ)
Tsiaras+(2018): H2O
Chachan+(2019): H2O/CH4(4.4σ)
Cubillos+(2022): H2O
Basilicata+(2024): NH3(5.0σ), H2O(3.4σ), CO2(3.2σ), CH4(2.6σ)
HAT-P-11b: A Super-Neptune Planet Transiting a Bright K Star in the Kepler Field
G. Á. Bakos+. ApJ 710:1724-1745 (2010).
HAT-P-18b (hot Saturn)
Fu+(2022): H2O, CH4(?)
Fournier-Tondreau+(2024): H2O(12.5σ), CO2(7.3σ), CH4(nd)
HAT-P-18b AND HAT-P-19b: Two Low-Density Saturn-Mass Planets Transiting Metal-Rich K Stars
J. D. Hartman+. ApJ 726:52 (2011).
HAT-P-41b (hot Jupiter)
Wakeford+(2020): TiO?, VO?
Lewis+(2020): VO/AlO/CrH or H–?
Sheppard+(2021): H2O(4.9σ), metal oxides(>2.7σ)
Jiang+(2024): TiO(Δln(Z)=21.02), CrH(Δln(Z)=3.73), MgH(Δln(Z)=3.73)
HAT-P-39b – HAT-P-41b: Three Highly Inflated Transiting Hot Jupiters
J. D. Hartman+. AJ 144:139 (2012).
HAT-P-65b (hot Jupiter)
Chen+(2021): TiO, VO(?)
HAT-P-65b and HAT-P-66b: Two Transiting Inflated Hot Jupiters and Observational Evidence for the Reinflation of Close-In Giant Planets
J. D. Hartman+. AJ 152:182 (2016).
HATS-5b (hot Saturn)
Allen+(2022): H2O
HATS-5b: A Transiting Hot Saturn from the HATSouth Survey
G. Zhou+. AJ 147:144 (2014).
HD 80606 b (hot Jupiter)
Coming Soon...
HD 80606 b, a planet on an extremely elongated orbit
D. Naif+. A&A 375:L27-L30 (2001).
HD 102195b
Guilluy+(2019): H2O(4.4σ), CH4(4.1σ)
The First Extrasolar Planet Discovered with a New-Generation High-Throughput Doppler Instrument
J. Ge+. ApJ 648:683 (2006).
HD 106315c (warm Neptune)
Kreidberg+(2022): H2O
Two Small Transiting Planets and a Possible Third Body Orbiting HD 106315
I. J. M. Crossfield+. AJ 153:255 (2017).
HD 129206b (hot Saturn)
Rafi+(2024): H2O(S.N=~4.8), HCN(nd)
The N2K Consortium. II. A Transiting Hot Saturn around HD 149026 with a Large Dense Core
B. Sato+. ApJ 633:465 (2005)
HD 179949b (hot Jupiter)
Brogi+(2014): CO+H2O(S/N=6.3)
Webb+(2020): CO+H2O(8.4σ) w/weak H2O(3.0σ)
Matthews+(2024): H2O, CO
First Results from the Anglo-Australian Planet Search: A Brown Dwarf Candidate and a 51 Peg-like Planet
C. G. Tinney+. ApJ 551:507-511 (2001).
HD 189733b (hot Jupiter)
Grillmair+(2007): H2O(nd), CH4(nd)
Tinetti+(2007): H2O
Swain+(2008): CH4, H2O
de Kok+(2013): CO(5σ), H2O(nd), CO2(nd), CH4(nd)
Birkby+(2013): H2O(4.8σ), H2O+CO2(5.1σ)
Brogi+(2016): CO+H2O(7.6σ)
Brogi+(2018): H2O(5.5σ)
Alonso-Floriano+(2019): H2O(S/N=6)
Cabot+(2019): H2O(4.8σ), CO(4.7σ), HCN(5.0σ)
Flowers+(2019): CO+H2O(8.2σ)
Boucher+(2021): H2O(5.9σ)
Finnerty+(2024): H2O(-1.7†), CO(-1.8†), CH4(-7.4†), NH3(-4.8†), HCN(-5.8†), H2S(-7.7†), 13CO(~3σ)
Inglis+(2024): SiO2(s), H2O, H2S
Zhang+(2025): H2O, CO2, CO, H2S
†=log mass-mixing ratio
ELODIE metallicity-biased search for transiting Hot Jupiters. II. A very hot Jupiter transiting the bright K star HD 189733
F. Bouchy+. A&A 444:L15 (2005).
HD 209458b (hot Jupiter)
Swain+(2009): H2O, CH4, CO2
Snellen+(2010): CO
Lenz+(2016): H+
3(nd)
Brogi+(2017): CO, H2O(?)
Giacobbe+(2021): H2O(9.6&sigma,8.2σ), CO(5.5σ), HCN(9.9σ), CH4(5.6σ,3.7σ), NH3(5.3σ,5.1σ), C2H2(6.1σ,5.9σ,3.3σ), CO2(nd)
Hawker+(2018): H2O(S/N=4.4), CO(S/N=5.1), H2O+CO(S/N=5.3), HCN(S/N=4.7)
Cassasaya-Barris+(2021): TiO(nd), VO(nd)
Xue+(2024): H2O, CO2, H2S(?), CH4(nd,<-5.6†), NH3(nd,<-4.2†), C2H2(nd,<-5.7†), HCN(nd,<-5.2†)
Blain+(2024): H2, C2H2(nd), CH4(nd), CO(nd), CO2(nd), H2S(nd), HCN(nd), NH3(nd)
†=log mass-mixing ratio
A Transiting "51 Peg-like" Planet
G. W. Henry+. ApJ 529, L41 (2000).
Detection of Planetary Transits Across a Sun-like Star
D. Charbonneau+. ApJ 529:L45 (2000).
HIP 99770b (super Jupiter)
Zhang+(2024): H2O(S/n=14), CO(S/N=23), NH3(nd), CH4(nd), 13CO(nd), CO2(nd),
Direct imaging and astrometric detection of a gas giant planet orbiting an accelerating star
T. Currie+. Science 380:198-203 (2023).
K2-18 b (sub-Neptune)
Tsiaras+(2019): H2O(3.6σ)
Benneke+(2019): H2O(-2.08†), N2(nd), CO(nd), CO2(nd), NH3(nd), CH4(nd)
Madhusudhan(2023)+: CH4(5σ), CO2(3σ), NH3(nd)
†=log mixing ratio
Stellar and Planetary Properties of K2 Campaign 1 Candidates and Validation of 17 Planets, Including a Planet Receiving Earth-like Insolation
B. T. Montet+. ApJ 809:24 (2015).
KELT-9b (ultra-hot Jupiter)
Changeat & Edwards+(2021): TiO, VO, FeH
Hayashi+(2024): TiO(-7.80†), VO(-9.60†)
†=log mixing ratio
A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host
B. S. Gaudi+. Nature 546:514-519 (2017).
KELT-20b (MASCARA-2b) (ultra-hot Jupiter)
Fu+(2022): H2O, CO
Nugroho+(2020): NaH(nd), MgH(nd), AlO(nd), SH(nd), CaO(nd), VO(nd), FeH(nd), TiO(nd)
Kesseli+(2020): FeH(S/N~3)
Johnson+(2023): VO(nd,<4σ), TiO(nd,<4σ), FeH(nd,<4σ), CaH(nd,<4σ)
Petz+(2024): VO(nd,S/N<3.4), CaH(nd,S/N<2.4), TiO(nd,S/N<2.6), NaH(nd,S/N<2.1), MgH(nd,S/N<1.8)
KELT-20b: A Giant Planet with a Period od P ~ 3.5 days Transiting the V ~ 7.6 Early A Star HD 185603
Lund+. AJ 154:194 (2017).
MASCARA-2 b - A hot Jupiter transiting the mV = 7.6 A-star HD 185603
G. J. J. Talens+. A&A 612:A57 (2018).
L98-59c (super-Earth)
Zhou+(2023): H2(nd)
Scarsdale+(2024): H2(nd), CH4(nd)
The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf
Kostov+. AJ 158:32 (2019).
L98-59d (super-Earth)
Zhou+(2023): H2(nd)
Gressier+(2024): Sulfur species
Banerjee+(2024): H2S, SO2
The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf
Kostov+. AJ 158:32 (2019).
LHS 1140b (temperate rocky super-Earth)
Cadieux+(2024): N2(2.3σ)
A temperate rocky super-Earth transiting a nearby cool star
Dittmann+. Nature 544:333-336 (2017).
LTT 3780c (TOI-732c) (sub-Neptune)
Cabot+(2024): CH4(2.2σ), NH3(nd)
A Pair of TESS Planets Spanning the Radius Valley around the Nearby Mid-M Dwarf LTT 3780
R. Cloutier+. AJ 160:3 (2020).
The CARMENES search for exoplanets around M dwarfs. Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780
G. Nowak+. A&A 642:A173 (2020).
MASCARA-1b (ultra-hot Jupiter)
Holmberg+(2022): CO(S/N=12.9), H2(S/N=5.3)
Ramkumar+(2023): CO(>15σ), H2O(>10σ)
MASCARA-1 b - A hot Jupiter transiting a bright mV = 8.3 A-star in a misaligned orbit
G. J. J. Talens+. A&A 606:A73 (2017).
τ Boötis Ab (hot Jupiter)
Lockwood+(2014): H2O
Pelletier+(2021): CO(-2.46‡), H2O(nd,<-5.66‡), CH4(nd,<-3.78‡), CO2(nd,<-3.99‡), HCN(nd,<-5.37‡), TiO(nd,<-7.54‡), C2H2(nd,<-4.88‡), NH3(nd,<-6.10‡)
Webb+(2022): H2O(-3.3‡),
Panwar+(2022): CO(-3.44‡), H2O(-5.13‡)
‡=log volume-mixing ratio
Three New "51 Pegasi-Type" Planets
R. P. Butler+. ApJ 474:L115 (1997).
TOI-270d (sub-Neptune)
Mikal-Evans+(2023): H2O(3σ)
Holmberg+(2024): CH4(3.8-4.9σ), CO2(2.9-3.9σ), H2O(1.6-4.4σ), CS2(2.3-3σ), NH3(nd)
A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270
M. N. Günther+. Nat Astron 3:1099-1108 (2019).
TOI-674b (warm Neptune)
Brande+(2022): H2O(2.9σ)
TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf
F. Murgas+. A&A 653:A60 (2021).
TOI-1431b (MASCARA-5b) (ultra-hot Jupiter)
Stangret+(2021): TiO(nd), VO(nd)
TOI-1431b/MASCARA-5b: A Highly Irradiated Ultra-Hot Jupiter Orbiting One of the Hottest & Brightest Known Exoplanet Host Stars
B. C. Addison+. AJ 162:292 (2021).
TYC 8998-760-1b (YSES 1b) (super-Jupiter)
Zhang+(2021): H2O, CO, 13CO(>6σ)
Zheng+(2024): 13CO(12.6σ)
The Young Suns Exoplanet Survey: Detection of a wide-orbit planetary-mass companion to a solar-type Sco-Cen member
A. J. Bohn+. MNRAS 492:431 (2020).
WASP-17b (hot Jupiter)
Sing+(2016): H2O
Sedaghati+(2016): H2O
Barstow+(2017): H2O
Alderson+(2222): H2O(>7σ), CO2(>7σ)
Saba+(2022): H2O, AlO, TiH
Grant+(2024): SiO2(s)(3.5-4.2σ)
WASP-17b: An Ultra-Low Density Planet in a Probable Retrograde Orbit
D. R. Anderson+. ApJ 164:2 (2010)
WASP-18b (hot Jupiter)
Arcangeli+(2018): CO, H2O
Gandhi+(2020): CO, H2O
Yan+(2023): CO
An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b
C. Hellier+. Nature 460:1098 (2009).
WASP-19b (hot Jupiter)
Huitson+(2013): H2O
Sedaghati+(2017): TiO
Sedaghati+(2021): H2O(nd), TiO(3.02σ)
WASP-19b: The Shortest Period Transiting Exoplanet Yet Discovered
L. Hebb+. ApJ 708:224 (2010).
WASP-20b (hot Jupiter)
Maimone+(2022): H2O
WASP-20b and WASP-28b: a hot Saturn and a hot Jupiter in near-aligned orbits around solar-type stars
D. R. Anderson+. A&A 575:A61 (2015).
WASP-31b (hot Jupiter)
Pinhas+(2019): H2O(2.2σ)
Braam+(2021): CrH(3.9σ), H2O(~3σ)
Flagg+(2023): CrH(5.6σ)
WASP-31b: a low-density planet transiting a metal-poor, late-F-type dwarf star
D. R. Anderson+. A&A 531:A60 (2011).
WASP-33b (ultra-hot Jupiter)
Haynes+(2015): TiO(?), H2O(?)
Nugroho+(2017): TiO
Serindag+(2017): TiO(disp,4.3σ)
Nugroho+(2017): OH(5.5σ), H2O(5.2σ)
von Essen+(2019): AlO(3.3σ)
Cont+(2021): TiO(conf,4.9σ)
Yan+(2022): CO
Yang+(2024): H2O
Mraz+(2024): CO(6.6σ)
Line-profile tomography of exoplanet transits. II. A gas-giant planet transiting a rapidly rotating A5 star
A. Collier Cameron+. MNRAS 407:507 (2010).
WASP-39b (hot Jupiter)
Wakeford+(2018): H2O
Ahrer+a(2023): CO2(26σ)
Ahrer+b(2023): H2O, CH4(nd)
Rustamkulov+(2023): H2O(33σ), CO2(28&sigma), CO(7&sigma), CH4(nd), SO2(2.7σ)
Alderson+(2023): CO2(28.5σ), H2O(21.5σ), SO2(4.8σ)
Powell+(2024): SO2, H2O
Carter+(2024):, H2O, CO, CO2, SO2
WASP-39b: a highly inflated Saturn-mass planet orbiting a late G-type star A40
F. Faedi+. A&A 531:A40 (2011).
WASP-43b (hot Jupiter)
Kreidberg+(2014): H2O
Feng+(2016): H2O, CH4(?)
Weaver+(2020): H2O
Chubb+(2020): H2O, AlO(>5σ)
Helling+(2020): minerals(?), salts(?)
Yang+(2023): H2O, CH4(nd)
Yang+(2024): H2O(6.5σ), NH3(4σ), CO(3.1σ)
WASP-43b: the closest-orbiting hot Jupiter
Hellier+. A&A 535:L7 (2011).
WASP-69b (warm Jupiter)
Tsiaras+(2018): H2O
Guilluy+(2022): CH4, NH3, CO, C2H2, H2O (all >3.2&sigma); HCN, CO2 (at <3σ)
Ouyang+(2023): TiO
Schlawin+(2024): H2O, CO, CO2, CH4(nd)
Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary
D. R. Anderson+. MNRAS 445:1114 (2014).
WASP-76b (ultrahot Jupiter)
Tabernero+(2021): TiO(nd), VO(nd), ZrO(nd)
Landman+(2021): OH(S/N=6.1)
Yan+(2023): CO
Weiner Mansfield+(2024): H2O(S/N=6.93), CO(S/N=6.47), OH(S/N=3.90)
Hood+ (2024): H2O(-4.52†), CO(-3.09†), C2H2(nd), HCN(nd), OH(nd)
†=log mass-mixing ratio
Three irradiated and bloated hot Jupiters: WASP-76b, WASP-82b, and WASP-90b
R. G. West+. A&A 585:A126 (2016).
WASP-77Ab (hot Jupiter)
Line+(2021): H2O, CO
Mansfield+(2022): H2O
WASP-77 Ab: A Transiting Hot Jupiter Planet in a Wide Binary System
P. F. L. Maxted+. Pubs Astron Soc Pacific 125:48 (2013).
WASP-80b (hot Jupiter)
Sedaghati+(2017): H2O(nd), CO(nd), CH4(nd)
Carleo+(2022): H2O(7.52σ), CH4(4.17σ), NH3(4.96σ), HCN(4.11σ), CO2(tent,4.45σ), C2H2(nd,3.39σ), CO(nd,4.62σ)
Bell+(2023): CH4(>6σ)
WASP-80b: a gas giant transiting a cool dwarf A80
A. H. M. J. Triaud+. A&A 551:A80 (2013).
WASP-103b (ultra-hot Jupiter)
Wilson+(2020): H2O(4.0σ)
Changeat(2022): H2, H2O, CO, CH4, FeH, TiO(nd), VO(nd)
WASP-103 b: a new planet at the edge of tidal disruption
M. Gillon+. A&A 562:L3 (2014).
WASP-107b (warm Neptune)
Kriedberg+(2018): H2O(6.7σ)
Dyrek+(2024): H2O(12σ), SO2(9σ), silicate(7σ), H2S(4σ), NH3(2-3σ), CO(2-3σ), CH4(nd)
Welbanks+(2024): CO2(29σ), H2O(21σ), SO2(9σ), CO(7σ), NH3O(6σ), CH4(5σ)
The discoveries of WASP-91b, WASP-105b and WASP-107b: Two warm Jupiters and a planet in the transition region between ice giants and gas giants
D. R. Anderson+. A&A 604:A110 (2017).
WASP-121b (ultra-hot Jupiter)
Evans+(2016): H2O(5.4σ), TiO, VO
Evans+(2017): H2O(5σ), TiO, VO
Tsiaras+(2018): H2O, TiO, VO
Mikal-Evans+(2019): VO(nd?)
Merritt+(2020): TiO(nd), VO(nd)
Goyal+(2020): H2O, VO
Ouyanng+(2023): H2O, TiO, VO
Hoejmakers+(2024): TiO(nd), VO(nd)
Wardenier+(2024): H2O, CO
Pelletier+(2025): H2O, CO
WASP-121 b: a hot Jupiter close to tidal disruption transiting an active F star
L. Delrez+. MNRAS 458:4025-4043 (2016).
WASP-122b (KELT-14b) (hot Jupiter)
Stangret+(2024): FeH(nd), H2O(nd), TiO(nd), VO(nd)
WASP-120 b, WASP-122 b, and WASP-123 b: Three Newly Discovered Planets from the WASP-South Survey
O. D. Turner+. Publ Astron Soc Pacific 128:064401 (2016).
WASP-127b (super-Neptune)
Chen+(2018): H2O
Skaf+(2020): H2O(-2.71†)
Spake+(2021): H2O(13.7σ), CO2, CO(?), CH4(?), FeH(?)
Boucher+(2023): H2O(5.3σ), OH(3σ), CO2(est. -3.7†), CO(nd,<-4.0†)
Kanumalla+(2024): H2O(8.67σ), CO(4.34σ)
†=log abundance
From dense hot Jupiter to low-density Neptune: The discovery of WASP-127b, WASP-136b, and WASP-138b
K. W. F. Lam+. A&A 599:A3 (2017).
WASP-166b (hot super-Neptune)
Lafarga+(2023): H2O
WASP-166b: a bloated super-Neptune transiting a V = 9 star
C. Hellier+. MNRAS 488:3067 (2019).
WASP-178b (ultra-hot Jupiter)
Lothringer+(2022): SiO
Cont+(2024): 12CO(S/N=8.9), H2O(S/N=4.9)
WASP-South hot Jupiters: WASP-178b, WASP-184b, WASP-185b, and WASP-192b
C. Hellier+, MNRAS 490:1479 (2019).
WASP-189b (ultra-hot Jupiter)
Prinoth+(2022): TiO
Yan+(2022): CO
WASP-189b: an ultra-hot Jupiter transiting the bright A star HR 5599 in a polar orbit
D. R. Anderson+. arXiv: 1809.04897 (2018). (in limbo)
The hot dayside and asymmetric transit of WASP-189 b seen by CHEOPS
Lendl+. A&A 643:A94.

Acronyms & Acronyms within Acronyms
2MASS 2 Micron All Sky Survey
GJ Gliese-Jahreiss catalog
HAT Hungarian Automatic Telescope
HAT-P HAT Planet
HATS HAT South
HD Henry Draper catalog
HIP Hipparcos catalog
KELT Kilodegree Extremely Little Telescope
LHS Luyten Half-Second catalog
LTT Luyten Two-Tenths catalog
MASCARA Multi-site All-Sky CAmeRA
TOI TESS Object of Interest
TESS Transiting Exoplanetary Survey Satellite
TYC Tyco Catalog
WASP Wide Angle Search for Planets

Maintained by DE Woon
Updated 12 January 2025