HD 154857
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Ara |
| Right ascension | 17h 11m 15.7219s |
| Declination | –56° 40′ 50.865″ |
| Apparent magnitude (V) | 7.25 |
| Distance | 223.55 ly (68.54 pc) |
| Spectral type | G5V |
| Other designations | |
|
HIP 84069, SAO 244491
|
|
HD 154857 is a star in the constellation Ara. Like our Sun, it is a yellow dwarf.
Contents |
[edit] Planets
There is one confirmed and one unconfirmed planet discovered in 2004 and 2007 respectively.
[edit] HD 154857 b
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 1.2±0.2 AU |
| Eccentricity | (e) | 0.47±0.02 |
| Orbital period | (P) | 409±1 d |
| Angular distance | (θ) | 17.518 mas |
| Longitude of periastron |
(ω) | 59±4° |
| Time of periastron | (T0) | 2450346±5 JD |
| Semi-amplitude | (K) | 50.4±1 m/s |
| Physical characteristics | ||
| Mass | (m) | > 1.8±0.4 MJ |
| Discovery information | ||
| Discovery date | 2004 | |
| Discoverer(s) | McCarthy et al. | |
| Detection method | Radial velocity | |
| Discovery status | Published | |
HD 154857 b is an extrasolar planet of gas giant mass that orbits the star in an eccentric orbit. This planet was detected by using Anglo-Australian Telescope (AAT) UCLE spectrometer.
[edit] HD 154857 c
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Eccentricity | (e) | 0.25 |
| Orbital period | (P) | 1900 d |
| Discovery information | ||
| Discovery date | 2007 | |
| Discoverer(s) | O' Toole | |
| Detection method | Radial velocity | |
| Discovery status | Unconfirmed | |
HD 154857 c is a possible planet discovered in 2007, together with HD 23127 b and HD 159868 b. More measurements are required to confirm its existence.
[edit] References
- McCarthy, Chris; Butler, R. Paul; Tinney, C. G.; Jones, Hugh R. A.; Marcy, Geoffrey W.; Carter, Brad; Penny, Alan J.; Fischer, Debra A. (2004). "Multiple Companions to HD 154857 and HD 160691". The Astrophysical Journal 617 (1): 575–579. doi:.
- O'Toole et al. (2007). "New Planets around Three G Dwarfs". The Astrophysical Journal 660 (2): 1636 – 1641. doi:. (web Preprint)
[edit] External links
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