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Revision as of 20:35, 16 January 2010 by Mike s (talk | contribs) (add reference section and references)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff) Orbits around the star HD108874 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 12 30 26.8829 |
| Declination | +22° 52′ 47.383″ |
| Apparent magnitude (V) | 8.76 |
| Characteristics | |
| Spectral type | G5 V |
| B−V color index | 0.764 |
| V−R color index | 0.4 |
| R−I color index | 0.4 |
| Variable type | ”None” |
| Astrometry | |
| Radial velocity (Rv) | -30.7 km/s |
| Proper motion (μ) | RA: -45.05 mas/yr Dec.: -105.39 mas/yr |
| Parallax (π) | 14.59 ± 1.24 mas |
| Distance | 220 ± 20 ly (69 ± 6 pc) |
| Absolute magnitude (MV) | 3.72 |
| Details | |
| Mass | 1 M☉ |
| Radius | 1.22 R☉ |
| Luminosity | 1.14 L☉ |
| Temperature | 5407 K |
| Metallicity | =+0.14 |
| Rotation | 37.82 days |
| Age | 7.26 Giga- years |
| Other designations | |
| BD+23°2466, HIP 61028, SAO 82344 | |
| Database references | |
| SIMBAD | data |
HD 108874 is a yellow dwarf star (spectral type G5 V) in the constellation of Coma Berenices. It is 223 light years from Earth and has two extrasolar planets that are possibly in a 4:1 orbital resonance.
Star
HD 108874 is 2.7 billion years older than our Sun. The star has a temperature of 5407 K and luminosity 1.14 solar. It has metallicity 1.38 times solar, meaning this star has greater iron abundance relative to hydrogen and helium. It has mass about the same as the Sun, but the radius is 22% greater.
Planetary system
In 2003, the jovian planet HD 108874 b was discovered in the United States by Paul Butler, Geoffrey Marcy, Steven Vogt, and Debra Fischer. This planet receives the insolation most similar to Earth of any extrasolar planet. In 2005, further observations revealed this star has another jovian planet orbiting further out, designated as HD 108874 c. Those two planets are in a 4:1 orbital resonance. This means if HD 108874 b orbits the star four times, then HD 108874 c orbits only once, because the orbital period for planet c is four times longer than planet b.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >1.36 ± 0.13 MJ | 1.051 ± 0.02 | 395.4 ± 2.5 | 0.07 ± 0.04 | — | — |
| c | >1.018 ± 0.3 MJ | 2.68 ± 0.25 | 1605.8 ± 88 | 0.25 ± 0.07 | — | — |
See also
References
- Butler; et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal. 582 (1): 455–466. doi:10.1086/344570.
{{cite journal}}: Explicit use of et al. in:|author=(help) - Vogt; et al. (2005). "Five New Multicomponent Planetary Systems". The Astrophysical Journal. 632 (1): 638–658. doi:10.1086/432901.
{{cite journal}}: Explicit use of et al. in:|author=(help)
External links
- "HD 108874". The Extrasolar Planets Encyclopaedia.
- "HD 108874". Extrasolar Visions.
- Extrasolar Planet Interactions by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona