HD 70573
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Hydra |
| Right ascension | 8h 22m 50s |
| Declination | +01° 51′ 34″ |
| Apparent magnitude (V) | +8.70 |
| Characteristics | |
| Spectral type | G1.2V |
| U-B color index | ? |
| B-V color index | ? |
| V-R color index | ? |
| R-I color index | ? |
| Variable type | none |
| Astrometry | |
| Radial velocity (Rv) | +19.5 km/s |
| Proper motion (μ) | RA: -54.00 mas/yr Dec.: -48.20 mas/yr |
| Parallax (π) | 21.9 mas |
| Distance | 149 ly (45.7 pc) |
| Absolute magnitude (MV) | +5.40 |
| Details | |
| Mass | 1 ± 0.1 M☉ |
| Radius | ? R☉ |
| Surface gravity (log g) | ? |
| Luminosity | 0.60 L☉ |
| Temperature | 5737 ± 70 K |
| Metallicity | 66% |
| Rotation | ? |
| Age | 0.101 ± 0.024 × 109 years |
| Other designations | |
|
BD+02º 1951, SAO 116694
|
|
HD 70573 is a 9th magnitude star in the constellation Hydra. It is 149 ly away from the earth. The star is young, only 101 million years old.
On March 19, 2007, an planet was announced, having been discovered by the radial velocity method. This is thus far the youngest host star discovered to have an orbiting planet.
[edit] HD 70573 b
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 1.76 ± 0.05 AU |
| Eccentricity | (e) | 0.4 ± 0.1 |
| Orbital period | (P) | 851.8 ± 11.6 d |
| Angular distance | (θ) | 38.512 mas |
| Longitude of periastron |
(ω) | 269.6 ± 14.3° |
| Time of periastron | (T0) | 2,452,106.54 ± 25.72 JD |
| Semi-amplitude | (K) | 149 m/s |
| Physical characteristics | ||
| Mass | (m) | >6.1 ± 0.4 MJ |
| Radius | (r) | >1.5 (Estimated) RJ |
| Temperature | (T) | >1200 (Estimated) K |
| Discovery information | ||
| Discovery date | March 19, 2007 | |
| Discoverer(s) | Setiawan et al. | |
| Detection method | radial velocity | |
| Discovery status | Published | |
The planet, designated as HD 70573 b orbits the youngest RV host star HD 70573. It is a mid-superjovian that orbits 76 percent further than Earth is to the Sun in an eccentric orbit. Due to its young age the planet is likely to be 1.5 times bigger than Jupiter and glowing red hot. But over the next few billion years it will eventually cool and shrink to a planet 90%-95% the size of Jupiter.
The discovery of the planet is important because it enables the study of debris disks around young stars in relation to presence of planets.
[edit] References
- Setiawan et al. (2007). "Evidence for a Planetary Companion around a Nearby Young Star" ([dead link] – Scholar search) 660: L145–L148.
[edit] External links
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