Astrometric measurements by theGaia spacecraft suggested the presence of aplanetary companion to 54 Cassiopeiae, seven times more massive thanJupiter and with anorbital period of 401 days (1.10 years).[9][6] This was later rejected by the Gaia team as a false positive caused by a software error.[10]Radial velocity observations also show no evidence for this planet.[11]
^abLatham, David W.; Stefanik, Robert P.; Torres, Guillermo; Davis, Robert J.; Mazeh, Tsevi; Carney, Bruce W.; Laird, John B.; Morse, Jon A. (2002-08-01). "A Survey of Proper-Motion Stars. XVI. Orbital Solutions for 171 Single-lined Spectroscopic Binaries".The Astronomical Journal.124 (2):1144–1161.Bibcode:2002AJ....124.1144L.doi:10.1086/341384.ISSN0004-6256.
^"Gaia DR3 known issues".ESA. 27 May 2024. Retrieved4 September 2024.During validation of the astrometric timeseries (epoch astrometry) for Gaia DR4, an error was discovered that had already had an impact on the Gaia DR3 non-single star results [...] The investigation showed that four specific targets suffered of this software bug and that the astrometric-orbit solutions of [...] 54 Cas [...] are false-positives as far as Gaia non-single star processing is concerned.
^Sozzetti, Alessandro (July 2024).Ground-based RV follow-up of Gaia DR3 astrometric exoplanet candidates around bright stars. EAS2024, European Astronomical Society Annual Meeting.Bibcode:2024eas..conf.1626S.
