The two planets, Kepler-26b and Kepler-26c, were discovered by transit method in late 2011,[6] and classified as small (sub-Neptune) gas giants in 2016.[7] In 2012, the planetary candidate Kepler-26d was also detected, and confirmed in 2014.[8] The planet Kepler-26e was discovered on a much wider orbit in 2014.[9]
^Steffen, Jason H.; Fabrycky, Daniel C.; Ford, Eric B.; Carter, Joshua A.; Desert, Jean-Michel; Fressin, Francois; Holman, Matthew J.; Lissauer, Jack J.; Moorhead, Althea V.; Rowe, Jason F.; Ragozzine, Darin; Welsh, William F.; Batalha, Natalie M.; Borucki, William J.; Buchhave, Lars A.; Bryson, Steve; Caldwell, Douglas A.; Charbonneau, David; Ciardi, David R.; Cochran, William D.; Endl, Michael; Everett, Mark E.; Gautier III, Thomas N.; Gilliland, Ron L.; Girouard, Forrest R.; Jenkins, Jon M.; Horch, Elliott; Howell, Steve B.; Isaacson, Howard; et al. (2012), "Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations", Monthly Notices of the Royal Astronomical Society, 421 (3): 2342, arXiv:1201.5412, Bibcode:2012MNRAS.421.2342S, doi:10.1111/j.1365-2966.2012.20467.x, S2CID11898578
^ abCubillos, Patricio; Erkaev, Nikolai V.; Juvan, Ines; Fossati, Luca; Johnstone, Colin P.; Lammer, Helmut; Lendl, Monika; Odert, Petra; Kislyakova, Kristina G. (2016), "An overabundance of low-density Neptune-like planets", Monthly Notices of the Royal Astronomical Society, 466 (2): 1868–1879, arXiv:1611.09236, doi:10.1093/mnras/stw3103, S2CID119408956
^Rowe, Jason F.; Bryson, Stephen T.; Marcy, Geoffrey W.; Lissauer, Jack J.; Jontof-Hutter, Daniel; Mullally, Fergal; Gilliland, Ronald L.; Issacson, Howard; Ford, Eric; Howell, Steve B.; Borucki, William J.; Haas, Michael; Huber, Daniel; Steffen, Jason H.; Thompson, Susan E.; Quintana, Elisa; Barclay, Thomas; Still, Martin; Fortney, Jonathan; Gautier, T. N.; Hunter, Roger; Caldwell, Douglas A.; Ciardi, David R.; Devore, Edna; Cochran, William; Jenkins, Jon; Agol, Eric; Carter, Joshua A.; Geary, John (2014). "Validation Ofkepler's Multiple Planet Candidates. III. Light Curve Analysis and Announcement of Hundreds of New Multi-Planet Systems". The Astrophysical Journal. 784 (1): 45. arXiv:1402.6534. Bibcode:2014ApJ...784...45R. doi:10.1088/0004-637X/784/1/45. S2CID119118620.
^Jontof-Hutter, Daniel; Ford, Eric B.; Rowe, Jason F.; Lissauer, Jack J.; Fabrycky, Daniel C.; Christa Van Laerhoven; Agol, Eric; Deck, Katherine M.; Holczer, Tomer; Mazeh, Tsevi (2015), Secure TTV Mass Measurements: Ten Kepler Exoplanets between 3 and 8 M🜨 with Diverse Densities and Incident Fluxes, arXiv:1512.02003, doi:10.3847/0004-637X/820/1/39, S2CID11322397