HD 46375 is an 8th magnitude K-type subgiant star located approximately 109 light-years away in the constellation of Monoceros. This star resembles a orange dwarf but which has a larger radius and luminosity indicating that fusion reactions in its core are starting to cease and the star is on its way becoming a red giant. Spectral type of the star is K1 IV. Its advanced evolutionary stage shows that it is considerably older than our Sun.
This star has sometimes been classified as a member of the NGC 2244 star cluster in the Rosette Nebula, but in reality it just happens to lie in the foreground. The distance to the cluster is much greater, about 4500 light years.
In 2000, a low-mass gas giant was found orbiting the star.
On March 29, 2000, the planet HD 46375 b with only three quarters the mass of Saturn was discovered by Marcy, Butler, and Vogt in California, together with 79 Ceti b. This planet was discovered using the "wobble method" or radial velocity method, which calculates the rate and shape of the stellar wobble caused by the revolving planet's gravity.
* List of extrasolar planets
1. ^ Marcy et al.; Butler, R. Paul; Vogt, Steven S. (2000). "Sub-Saturn Planetary Candidates of HD 16141 and HD 46375". The Astrophysical Journal Letters 536 (1): L43–L46. doi:10.1086/312723. http://www.iop.org/EJ/article/1538-4357/536/1/L43/005174.html.
* "Notes for star HD 46375". The Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=HD+46375. Retrieved 2008-08-23.