The companion to HD 131664 (discovered in 2008) has been shown to have a true mass much greater than its minimum mass, and is thus a low-mass star rather than a planet.[15] Similarly, a 2017 study showed 2MASS J21402931+1625183 b to actually have a mass of 69+8 −9MJ,[16] making it a high-mass brown dwarf or a low-mass red dwarf.
^ abRosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; Isaacson, Howard T.; Howard, Andrew W.; Dedrick, Cayla M.; Sherstyuk, Ilya A.; Blunt, Sarah C.; Petigura, Erik A.; Knutson, Heather A.; Behmard, Aida; Chontos, Ashley; Crepp, Justin R.; Crossfield, Ian J. M.; Dalba, Paul A.; Fischer, Debra A.; Henry, Gregory W.; Kane, Stephen R.; Kosiarek, Molly; Marcy, Geoffrey W.; Rubenzahl, Ryan A.; Weiss, Lauren M.; Wright, Jason T. (2021), "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades", The Astrophysical Journal Supplement Series, 255 (1): 8, arXiv:2105.11583, Bibcode:2021ApJS..255....8R, doi:10.3847/1538-4365/abe23c, S2CID235186973
^Butler, R. Paul; Johnson, John Asher; Marcy, Geoffrey W.; Wright, Jason T.; Vogt, Steven S.; Fischer, Debra A. (2006), "A Long-Period Jupiter-Mass Planet Orbiting the Nearby M Dwarf GJ 8491", Publications of the Astronomical Society of the Pacific, 118 (850): 1685–1689, arXiv:astro-ph/0610179, Bibcode:2006PASP..118.1685B, doi:10.1086/510500, S2CID14787596
^Reffert, S.; Quirrenbach, A. (March 2011). "Mass constraints on substellar companion candidates from the re-reduced Hipparcos intermediate astrometric data: nine confirmed planets and two confirmed brown dwarfs". Astronomy & Astrophysics. 527: 22. arXiv:1101.2227. Bibcode:2011A&A...527A.140R. doi:10.1051/0004-6361/201015861. S2CID54986291. A140.
^Pepe, F.; Mayor, M.; Queloz, D.; Benz, W.; Bonfils, X.; Bouchy, F.; Lo Curto, G.; Lovis, C.; Mégevand, D.; Moutou, C.; Naef, D.; Rupprecht, G.; Santos, N. C.; Sivan, J.-P.; Sosnowska, D.; Udry, S. (2004), "The HARPS search for southern extra-solar planets", Astronomy & Astrophysics, 423: 385–389, arXiv:astro-ph/0405252, doi:10.1051/0004-6361:20040389, S2CID59157984