HD 46375

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**HD 46375**
Observation data Epoch 2000
Constellation (pronunciation)	Monoceros
Right ascension	6^h 33^m 12.62^s
Declination	+5° 27' 46.53"
Apparent magnitude (V)	7.84
Distance	108.9 ly (33.41 pc)
Spectral type	K1IV
Other designations
BD+05°1295, HIP 31246

HD 46375 is an 8th magnitude star in the constellation of Monoceros. It is an orange subgiant, a star resembling an 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.

HD 46375 is slightly more than 100 light years distant. It 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.

[edit] HD 46375 b

**HD 46375 b**
Orbital elements
Extrasolar planet		List of extrasolar planets
Semimajor axis	(a)	0.0398±0.0023 AU
Eccentricity	(e)	0.063±0.026
Orbital period	(P)	3.023573±0.000065 d
Angular distance	(θ)	1 mas
Longitude of periastron	(ω)	114±24°
Time of periastron	(T₀)	2,451,071.53±0.19 JD
Semi-amplitude	(K)	33.65±0.74 m/s
Physical characteristics
Mass	(m)	>0.226±0.019 M_J
Discovery information
Discovery date		March 29, 2000
Discoverer(s)		Marcy, Butler, Vogt
Detection method		Radial velocity
Discovery site		Calif., USA
Discovery status		Published

HD 46375 b is a planet of the star HD 46375. With 79 Ceti b on March 29, 2000, it was the first known extrasolar planet less massive than Saturn orbiting a normal star. The planet is a "hot Jupiter", a type of planet that orbits very close to its parent star. In this case the orbital distance is only a tenth that of the planet Mercury. No transit of the planet has been detected, so its inclination must be less than 83°. Because the inclination is unknown, the true mass of the planet is not known. However, it is very unlikely that it is much larger than the calculated minimum mass.