14 Herculis is anorange dwarfstar of thespectral type K0V. The star has about 98 percent of themass, 97 percent of theradius, and only 67 percent of theluminosity of theSun. The star appears to be 2.7 times as enriched with elements heavier thanhydrogen (based on its abundance ofiron), in comparison to the Sun.[4] It may have been the most metal rich star known as of 2001.[8]
In 1998 a planet,14 Herculis b was discovered orbiting 14 Herculis viaradial velocity.[9][10] This was formally published in 2003.[11] The planet has an eccentric orbit with a period of 4.8 years.[12] In 2005, a possible second planet was proposed, designated14 Herculis c.[13] The parameters of this planet were very uncertain, but an initial analysis suggested that it was in the 4:1resonance with the inner planet, with an orbital period of almost 19 years at an orbital distance of 6.9 AU.[12] The existence of the planet 14 Herculis c was confirmed in 2021, along with a rough orbit determination.[14]
A 2021 study combining radial velocity andastrometry found that the planetary orbits are not coplanar, which may indicate a strong planet-planet scattering event in the past.[4] Albeit one study using astrometry has found inclinations consistent with aligned orbits,[15] newer research includingJames Webb Space Telescope observations confirm the orbits are misaligned.[16][17] The planets are strongly interacting with each other. Their inclinations and eccentricities oscillate due to these gravitational interactions.[17]
There are signs of a third candidate planet with a period of about 10 years, but this signal is most likely related to the star's magnetic activity cycle.[16]
^Inclinations: Xiaoet al. (2025)[18] 14 Her b mass, axis and period: Fenget al. (2024)[19] 14 Her b eccentricity and inclination: Xiaoet al. (2025)[18] 14 Her c's other properties: Bardalez Gagliuffiet al. (2025)[17]
^Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars".Astrophysical Journal Supplement Series.71: 245.Bibcode:1989ApJS...71..245K.doi:10.1086/191373.
^Mayor, M.; et al. (1998). "Searching for giant planets at the Haute-Provence Observatory". In Hearnshaw, J. B.; Scarfe, C. D. (eds.).Precise Stellar Radial Velocities. IAU Colloqu. 170. San Francisco: ASP.
^Rosenthal, 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
