HD 122430
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Hydra |
| Right ascension | 14h 02m 22.782s |
| Declination | −27º 25' 47.18″ |
| Apparent magnitude (V) | 5.48 |
| Absolute magnitude (V) | -0.17 |
| Distance | 440 ly (135 pc) |
| Spectral type | K3III |
| Other designations | |
HD 122430 is an orange giant star located in the constellation Hydra on the celestial sphere. The star has completely run out of the hydrogen fuel, which keeps the star stable, although its age is only 3.1 billion years old, younger than the Sun’s 4.6 billion years. HD122430 has a mass of 1.4 times and radius of 22.9 times that of the sun. Despite its younger age, it has slightly lower metallicity, approximately 90%. The temperature of its surface [photosphere] is approximately 4300 Kelvins.
[edit] HD 122430 b
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 1.02 AU |
| Eccentricity | (e) | 0.68±0.09 |
| Orbital period | (P) | 344.95±1.08 d |
| Angular distance | (θ) | 7.56 mas |
| Longitude of periastron |
(ω) | 91.04±17.27° |
| Time of periastron | (T0) | 2451986.71±3.75 JD |
| Semi-amplitude | (K) | 2.02 m/s |
| Physical characteristics | ||
| Mass | (m) | >3.71 MJ |
| Discovery information | ||
| Discovery date | 2003 | |
| Discoverer(s) | Setiawan et al. | |
| Detection method | radial velocity | |
| Discovery site | Spain | |
| Discovery status | Published | |
HD 122430 b is a giant planet orbiting around the giant star HD 122430. It is a superjovian-type with mass greater than 3.71 times that of Jupiter. This planet located at a distance of 1.02 astronomical units away from its star, which is very similar to the Earth’s distance from the Sun. Despite of this, the planet is too hot for it to have liquid water or life on any of the planet’s moons. Also, its orbit is highly eccentric, around 68%. At periastron, the orbital distance from its parent star is 0.33 AU. At apastron, the distance is 1.71 AU. If this planet were located in our own solar system, its orbit would ranges from just within Mercury’s orbit to just beyond Mars’s orbit.
In Spain, Setiawan discovered this planet in 2003, using his radial velocity method.
[edit] References
- Setiawan, J. (2003). "Planets around evolved stars": 595-598.
[edit] External links
- Notes for star HD 122430. The Extrasolar Planets Encyclopaedia. Retrieved on December 7, 2007.
- Notes for planet HD 122430 b. The Extrasolar Planets Encyclopaedia. Retrieved on December 7, 2007.
- HD 122430 -- Star. SIMBAD. Retrieved on December 7, 2007.
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