In 2020, astronomers announced the discovery of radio emissions from the star which are consistent with the star having a magnetic interaction with a planet approximately the size of Earth, revolving in a 1-5 day long orbit.[8][9][10][11][12][13] Such an interaction would be analogous to a scaled-up version of the Jupiter-Io magnetic interaction, with GJ 1151 taking the role of Jupiter and its planet the role of Io.
Two papers published only a month apart in 2021 discussed planet detection at GJ 1151 by the radial velocity method. One claimed the detection of a planet with a minimum mass of 2.5 ME and a period of 2 days, supporting the radio emission detection,[14] while the other was unable to confirm this candidate planet, finding that the 2-day signal is likely caused by long-term variability, possibly connected to a more distant planet.[15] This second study placed an upper limit of 0.7-1.2 ME on the minimum masses of any undetected planets with periods from 1-5 days.[15]
In 2023, a different planet was found, with a minimum mass of 10.6 ME and a 390-day orbit, along with additional radial velocity variations. This new planet was referred to by the preprint version of the discovery paper as GJ 1151 b, but the published version of the paper, as well as the NASA Exoplanet Archive, refer to it as GJ 1151 c to differentiate it from the previous candidate. While the presence of a short-period planet associated with the radio emissions could not be completely ruled out, if such a planet exists its minimum mass must be less than 1.2 ME.[4]
^Mahadevan, Suvrath; Stefánsson, Gudmundur; Robertson, Paul; Terrien, Ryan C.; Ninan, Joe P.; Holcomb, Rae J.; Halverson, Samuel; Cochran, William D.; Kanodia, Shubham; Ramsey, Lawrence W.; Wolszczan, Alexander; Endl, Michael; Bender, Chad F.; Diddams, Scott A.; Fredrick, Connor; Hearty, Fred; Monson, Andrew; Metcalf, Andrew J.; Roy, Arpita; Schwab, Christian (2021), "The Habitable-zone Planet Finder Detects a Terrestrial-mass Planet Candidate Closely Orbiting Gliese 1151: The Likely Source of Coherent Low-frequency Radio Emission from an Inactive Star", The Astrophysical Journal Letters, 919 (1): L9, arXiv:2102.02233, Bibcode:2021ApJ...919L...9M, doi:10.3847/2041-8213/abe2b2, S2CID231802021
^ abPerger, M.; Ribas, I.; Anglada-Escudé, G.; Morales, J. C.; Amado, P. J.; Caballero, J. A.; Quirrenbach, A.; Reiners, A.; Béjar, V. J. S.; Dreizler, S.; Galadí-Enríquez, D.; Hatzes, A. P.; Henning, Th.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Montes, D.; Pallé, E.; Rodríguez-López, C.; Schweitzer, A.; Zapatero Osorio, M. R.; Zechmeister, M. (2021), "The CARMENES search for exoplanets around M dwarfs", Astronomy & Astrophysics, 649: L12, arXiv:2103.10216, Bibcode:2021A&A...649L..12P, doi:10.1051/0004-6361/202140786, S2CID126038821
