Gliese 317
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Pyxis |
| Right ascension | 08h 40m 59.21s |
| Declination | –23° 27′ 22.6″ |
| Apparent magnitude (V) | 12.0 |
| Distance | 29.9 ly (9.17 pc) |
| Spectral type | M3.5 |
| Other designations | |
Gliese 317 is a red dwarf star of magnitude 12 located in constellation Pyxis. The distance from the solar system is almost 30 light years away with the absolute magnitude of 12.2, corresponding to visual luminosity of 0.1% Sun.
Contents |
[edit] Planets
There is one confirmed and one unconfirmed planet, both discovered in July 2007.
[edit] Gliese 317 b
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Discovery
|
|
|---|---|
| Discovered by | Johnson et al. |
| Discovery site | Keck Observatory |
| Discovery date | July 2007 |
| Detection method | Doppler Spectroscopy |
| Periastron | 0.767 AU |
| Apastron | 1.133 AU |
| Semi-major axis | 0.95 AU |
| Eccentricity | 0.193 ± 0.06 |
| Orbital period | 692.9 ± 4 d (1.9 ± 1.1 y) |
| Average orbital speed | 14.82 km/s |
| Angular distance | 103.599 mas |
| Longitude of periastron | 344 ± 10° |
| Time of periastron | 2451639 ± 30 JD |
| Semi-amplitude | 57.3 m/s |
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Physical characteristics
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| Mass | >1.2 MJ |
Gliese 317 b is a jovian planet that orbits about 95% the distance between Earth to the Sun. Despite of this, it takes about 1.9 years, corresponding to slow orbital velocity of 14.82 km/s.
There is a possible second planet in the system, if it exist, the orbital parameters would change for the first planet. It would have an orbital period of 673.4 days and eccentricity of 0.25.
[edit] Gliese 317 c
|
Discovery
|
|
|---|---|
| Discovered by | Johnson et al. |
| Discovery site | Keck Observatory |
| Discovery date | July 2007 (TBC) |
| Detection method | Radial velocity |
| Eccentricity | 0.42 |
| Orbital period | 2700 d (7.4 y) |
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Physical characteristics
|
|
| Mass | >0.83 MJ |
Gliese 317 c is a possible jovian planet at least 83% the mass of Jupiter. The semi-major axis is unknown, relatively typical for unconfirmed planets. The eccentricity of the orbit is 42% and have orbital period of 7.4 years.
[edit] References
- John A. Johnson, R. Paul Butler, Geoffrey W. Marcy, Debra A. Fischer, Steven S. Vogt, Jason T. Wright, Kathryn M. G. Peek (2007). "A New Planet Around an M Dwarf: Revealing a Correlation Between Exoplanets and Stellar Mass". ARXIV: 27.
[edit] External links
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