HD 168443
From Wikipedia, the free encyclopedia
Observation data Epoch 2000 |
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Constellation (pronunciation) |
Serpens |
Right ascension | 18h 20m 04.11s |
Declination | -09° 35' 34.6" |
Apparent magnitude (V) | 6.92 |
Distance | 123.5 ly (37.88 pc) |
Spectral type | G5IV |
Other designations | |
GJ 4052, BD-09°4692,
HIP 89844 |
HD 168443 is a yellow dwarf star of (spectral type G5) about the mass of our Sun. It is in the constellation of Serpens Cauda, 123 light years from our solar system. It is known to be orbited by one large planet and a brown dwarf.
Contents |
[edit] HD 168443 b
Orbital elements | ||
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Semi-major axis a: | 0.29 AU | |
Eccentricity e: | 0.529 ± 0.02 | |
Orbital period P: | 58.116 ± 0.001 d | |
Inclination i: | ?° | |
Angular distance θ: | 7.656 mas | |
Longitude of periastron ω: |
172.9° | |
Time of periastron τ: | 2,451,616.36 ± 0.02 JD | |
Semi-amplitude K: | 475.9 ± 1.6 m/s | |
Physical characteristics | ||
Mass: | >7.2 ± 0.4 MJ | |
Radius: | ? RJ | |
Density: | ? kg/m³ | |
Gravity: | ? g | |
Temperature: | ? K | |
Discovery | ||
Discovery date: | 1998 | |
Discovery site: | ||
Detection method(s): | Radial velocity | |
Discoverer(s): | Butler, Marcy | |
Other catalogue | ||
HD 168443 b is a planet seven times as massive as Jupiter. Given the high mass, this planet is likely to be a gas giant, or possibly a small brown dwarf depending on the orbital inclination. It orbits closer to its star than Mercury does to the Sun, and its surface temperature is likely to be very high.
[edit] HD 168443 c
Orbital elements | ||
---|---|---|
Semi-major axis a: | 2.87 AU | |
Eccentricity e: | 0.228 ± 0.005 | |
Orbital period P: | 1739.5 ± 3.98 d | |
Inclination i: | 150° | |
Angular distance θ: | 75.768 mas | |
Longitude of periastron ω: |
63° | |
Time of periastron τ: | 2,452,015.5 ± 3.6 JD | |
Semi-amplitude K: | 298.0 ± 1.2 m/s | |
Physical characteristics | ||
Mass: | 34 ± 12 MJ | |
Radius: | ? RJ | |
Density: | ? kg/m³ | |
Gravity: | ? g | |
Temperature: | ? K | |
Discovery | ||
Discovery date: | 2001 | |
Discovery site: | ||
Detection method(s): | Radial velocity | |
Discoverer(s): | Butler, Marcy et al. Udry, Mayor et al. |
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Other catalogue | ||
HD 168443 c is a brown dwarf orbiting beyond the outer edge of the habitable zone of HD 168443. Radial velocity measurements give a minimum mass 17.1 times that of Jupiter. The best-fit astrometric solution using data from the Hipparcos mission gives an inclination of 150° and a mass 34 times that of Jupiter.
[edit] References
- Marcy, G., Butler, R., Vogt, S., Liu, M., Laughlin, G., Apps, K., Graham, J., Lloyd, J., Luhman, K., Jayawardhana, R. (2005). "Two Substellar Companions Orbiting HD 168443" (abstract). Astrophysical Journal 555: 418 – 425. doi: .
- Reffert, S., Quirrenbach, A. (2006). "Hipparcos astrometric orbits for two brown dwarf companions: HD 38529 and HD 168443" (abstract). Astronomy and Astrophysics 449: 699 – 702. doi: .