HD 90156 is a star with an orbiting exoplanet in the constellationHydra. Based on parallax measurements, it is located at a distance of 71.6 light years from the Sun.[2] The system is drifting further away with a heliocentric radial velocity of 27 km/s.[5] The apparent visual magnitude of this star is 6.92,[1] which is places it near the lower limit of visibility to the naked eye. A survey in 2015 ruled out the existence of any stellar companions at projected distances above 5 AU.[10]
This star was designated as Gamma Antliae by Lacaille, and Gould intended to keep it in the Antlia constellation. However, the delineating of constellation boundaries in 1930 saw it transferred to Hydra.[11]
In 2011, an exoplanet was found in an eccentric orbit around the host star using Doppler spectroscopy. As the inclination of its orbital plane is unknown, only a lower bound on its mass can be determined. It has at least 18 times the mass of the Earth. The exoplanet is orbiting its host star with a separation of 0.25 AU and a period of 50 days.[4]
^Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, VA: The McDonald & Woodward Publishing Company. p. 29. ISBN978-0-939923-78-6.