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| Being that '''HD 108874 b''' is a ] 1.36 (+/-0.13) times the mass of ], | Being that '''HD 108874 b''' is a ] 1.36 (+/-0.13) times the mass of ], | ||
| and that it has the most Earth-like ] to date (12/2007), it has the best probablity of having ] ]. | and that it has the most Earth-like ] to date (12/2007), it has the best probablity of having ] ]. | ||
| <br clear="all"/> | <br clear="all"/> | ||
Revision as of 03:50, 1 January 2008
| Observation data Epoch 2000 Equinox 2000 | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 12 30 |
| Declination | +22° 52' 47.383" |
| Apparent magnitude (V) | 8.76 |
| Characteristics | |
| Spectral type | G5 V |
| U−B color index | ? |
| B−V color index | ? |
| Variable type | ? |
| Astrometry | |
| Proper motion (μ) | RA: -45.05 mas/yr Dec.: -105.39 mas/yr |
| Parallax (π) | 30.71 ± 0.81 mas |
| Distance | 106 ly (30.6 pc) |
| Absolute magnitude (MV) | 3.72 |
| Details | |
| Mass | 1 M☉ |
| Radius | 1.22 R☉ |
| Luminosity | ? L☉ |
| Temperature | 5407 K |
| Metallicity | =+0.14 |
| Rotation | ? |
| Age | 7.26 Giga- years |
| Other designations | |
| BD+23°2466,HIP 61028 | |
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.
Planets
HD 108874 b
| Orbital characteristics | |
|---|---|
| Semi-major axis | 1.051 ± 0.02 |
| Eccentricity | 0.07 ± 0.04 |
| Orbital period (sidereal) | 395.4 ± 2.5 |
| Inclination | ? |
| Physical characteristics | |
| Mass | >1.36 ± 0.13 |
| Mean density | ? |
HD 108874 b is a gas giant discovered in 2003 that orbits in the star's habitable zone.
Of all 270 planets found so far (Dec.2007) it has the most Earth-like insolation.
Using the following formulas, drived from Luminosity(Watts) = 4pi·RaT = 4pi·df
the Average, Apastron, and Periastron heat received by this planet can be calculated:
R, Star Radius (km)
a, Stefan-Boltzmann constant (5.67051e-8)
T, Star Effective temperature °K
f, Irradiance, Solar Constant (W/m)
d, Semi-major axis (meters)
Periastron Flux:
Average Flux:
Apastron Flux:
| Planet Distance | Insolation (W/m) | % of Earth's. |
|---|---|---|
| HD 108874 b Apastron Flux | 1234.655541 | 90.12% |
| Earth's Aphelion Flux | 1325.277174 | 93.74% |
| Earth's Average Flux | 1369.938576 | 100.00% |
| HD 108874 b Average Flux | 1413.557129 | 103.18% |
| Earth's Perihelion Flux | 1416.896227 | 103.43% |
| HD 108874 b Periastron Flux | 1634.359035 | 119.30% |
| Venus' Aphelion Flux | 2,585.411 | 188.72% |
| Venus' Average Flux | 2,620.693 | 191.30% |
| Venus' Perihelion Flux | 2,656.70 | 193.93% |
Being that HD 108874 b is a gas giant 1.36 (+/-0.13) times the mass of Jupiter, and that it has the most Earth-like Insolation to date (12/2007), it has the best probablity of having habitable moons.
HD 108874 c
| Orbital characteristics | |
|---|---|
| Semi-major axis | 2.68 ± 0.25 |
| Eccentricity | 0.25 ± 0.07 |
| Orbital period (sidereal) | 1605.8 ± 88 |
| Inclination | ? |
| Physical characteristics | |
| Mass | >1.018 ± 0.3 |
| Mean density | ? |
HD 108874 c is a gas giant discovered in 2005 which orbits beyond the star's habitable zone.
References
- Butler; et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal. 582: 455–466.
{{cite journal}}: Explicit use of et al. in:|author=(help) - Vogt; et al. (2005). "Five New Multicomponent Planetary Systems". The Astrophysical Journal. 632: 638–658.
{{cite journal}}: Explicit use of et al. in:|author=(help)
The Extrasolar Planets Encyclopedia:
http://exoplanet.eu/star.php?st=HD+108874
http://exoplanet.eu/planet.php?p1=HD+108874&p2=b
http://exoplanet.eu/planet.php?p1=HD+108874&p2=c
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