HD 108147

Starbox short
name=HD 108147
epoch=2000
constell=Crux
ra=12^h 25^m 46.27^s
dec=-64° 01' 19.52"
spectral=F8/G0V
appmag_v=7.003
dist_ly=125.7
dist_pc=38.57
names=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 in 2000. It should not be confused with HD 107148, which also has an extrasolar planet discovered in 2006 in Virgo constellation.

HD 108147 b

Extrasolar Planet
name=HD 108147 b
semimajor=0.104
eccentricity=0.498 ± 0.025
period=10.901 ± 0.001
inclination=?
ang_dist=2.696
long_peri=318 ± 3.03
t_peri=2,451,591.6 ± 0.1
semi-amp=25.1 ± 6.1
mass=>0.40
radius=?
density=?
gravity=?
temperature=920
discoverers=Pepe, Mayor,
Galland et al.
discovery_date=2000

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.

ee also

* HD 107148

References

*cite journal | url=http://www.edpsciences.org/papers/aa/full/2002/23/aah3477/aah3477.html |author=Pepe et al.|title=The CORALIE survey for southern extra-solar planets VII Two short-period Saturnian companions to HD 108147 and HD 168746|journal = Astronomy and Astrophysics | volume=388 | year=2002 | pages=632–638 | doi=10.1051/0004-6361:20020433

External links

* [http://simbad.u-strasbg.fr/Simbad SIMBAD] [http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=HD+108147 star entry] [http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=HD+108147+B planet entry]
* [http://www.obspm.fr/encycl/encycl.html The Extrasolar Planets Encyclopaedia] [http://www.obspm.fr/encycl/HD108147.html entry]
* [http://www.extrasolar.net Extrasolar Visions] [http://www.extrasolar.net/planettour.asp?StarCatId=normal&PlanetId=135 entry]