HD 108147

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**HD 108147**
Observation data Equinox 2000
Constellation	Crux
Right ascension	12^h 25^m 46.27^s
Declination	-64° 01' 19.52"
Apparent magnitude (V)	7.003
Distance	125.7 ly (38.57 pc)
Spectral type	F8/G0V
Other designations
CD−63°757, CPD−63°2270, HIP 60644, LTT 4696, SAO 251899

HD 108147 is a 7th magnitude star in the constellation of Crux. It is either a yellow-white or yellow dwarf (the line is arbitrary and the colour difference is only from classification, not real), slightly brighter and more massive than our Sun. The spectral type is F8 V or G0 V. The star is also younger than the Sun. Due to its distance, about 130 light years, it is too dim to be visible with unaided eye; with binoculars it is an easy target. However, due to its southerly location it is not visible in the northern hemisphere except for the tropics.

The star is special since an extrasolar planet has been detected orbiting it.

[edit] HD 108147 b

**HD 108147 b**
Orbital elements

Semi-major axis a:	0.104 AU
Eccentricity e:	0.498 ± 0.025
Orbital period P:	10.901 ± 0.001 d
Inclination i:	?°
Longitude of periastron ω:	318 ± 3.03°
Time of periastron τ:	2,451,591.6 ± 0.1 JD
Physical characteristics
Mass:	>0.40 M_J
Radius:	? R_J
Density:	? kg/m³
Temperature:	? K
Discovery
Discovery date:	2000
Detection method(s):
Discoverer(s):	Pepe, Mayor, Galland et al.

The planet, HD 108147 b is a gas giant with a minimum mass about half that of Jupiter. It orbits the star in a very tight "torch orbit". The distance between the planet and the star is only a tenth of the distance between Earth and the Sun (0.1AU). A number of such worlds are known to exist, but the eccentricity of this planet is unusually high. Planets orbiting very close to their parent stars usually have round orbits because of the tidal forces between the bodies.