HD 6434
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| Observation data Equinox 2000 |
|
|---|---|
| Constellation | Phoenix |
| Right ascension | 1h 4m 40.15s |
| Declination | -39° 29' 17.58" |
| Apparent magnitude (V) | 7.72 |
| Distance | 131.5 ly (40.34 pc) |
| Spectral type | G2/G3V |
| Other designations | |
|
CD-40°239, HIP 5054
|
|
HD 6434 is an 8th magnitude star in the constellation of Phoenix. It is a very Sun-like yellow dwarf star, only younger being 3,200 million years old. Yellow dwarfs are not very luminous, so at a distance of 130 light years this star is not visible to the unaided eye. With binoculars it should be readily visible.
In 2000 a planet was observed orbiting the star.
[edit] HD 6434 b
| Extrasolar planet | Lists of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 0.14 AU |
| Eccentricity | (e) | 0.17±0.03 |
| Orbital period | (P) | 21.998±0.009 d |
| Inclination | (i) | ?° |
| Longitude of periastron |
(ω) | 156±11° |
| Time of periastron | (τ) | 2,451,490.8 ±0.6 JD |
| Physical characteristics | ||
| Mass | (m) | >0.39 MJ |
| Radius | (r) | ? RJ |
| Density | (ρ) | ? kg/m3 |
| Temperature | (T) | ? K |
| Discovery information | ||
| Discovery date | 2000 | |
| Discoverer(s) | Queloz et al. | |
| Detection method | Radial velocity | |
| Discovery status | Published | |
HD 6434 b is an extrasolar planet orbiting the star. It has a minimum mass about half that of Jupiter. It orbits the star very close, over 2.5 times as close as Mercury orbits the Sun. For this reason it completes one orbit in only 22 days. Unlike true "hot Jupiters" like 51 Pegasi b, HD 6434 b does not have a circular orbit, but rather an eccentric one.
By studying observations taken by the Hipparcos astrometric mission, a group of scientists proposed that the planet has an inclination of 179.9° (almost exactly face-on) and a mass of 196 Jupiters. If that was the case, the planet would be a red dwarf instead. However, the data was anything but conclusive, and statistically it is extremely unlikely to lie in such position. But because the inclination is unknown, the true mass of the planet is not known. Still, it is very probable that that the object is a true planet.
[edit] References
- Mayor et al. (2004). "The CORALIE survey for southern extra-solar planets XII. Orbital solutions for 16 extra-solar planets discovered with CORALIE". Astronomy and Astrophysics 415: 391-402.
[edit] External links
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