Misplaced Pages

HD 108874: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editNext edit →Content deleted Content addedVisualWikitext
Revision as of 23:55, 8 June 2008 editGabrielVelasquez (talk | contribs)2,704 edits →HD 108874 b← Previous edit Revision as of 00:18, 9 June 2008 edit undoGabrielVelasquez (talk | contribs)2,704 edits →HD 108874 bNext edit →
Line 72: Line 72:
Of all 293 planets found so far (June/07) it has the most Earth-like ]. Of all 293 planets found so far (June/07) it has the most Earth-like ].


<br /><br /><br /><br /><br /><br /><br />
⚫ ----
Using the following formulas, derived from ](]s) = 4pi·R<sup>2</sup>aT<sup>4</sup> = 4pi·d<sup>2</sup>f Using the following formulas, derived from ](]s) = 4pi·R<sup>2</sup>aT<sup>4</sup> = 4pi·d<sup>2</sup>f


Line 86: Line 88:
d, ] (meters) d, ] (meters)


<br /><br /><br /><br />
⚫ ----


'''Periastron Flux:'''<math>f_p= \frac{( (1.22 \times 6.955 \times 10^8 )^2 ) \times (5.67051 \times 10^{-8}) \times (5407^4 K)} { ( ( 1.051- ( 1.051\times 0.07 ) ) \times 149597876600 m)^2 }</math>
'''Periastron Flux:'''
<math>(((1.22*6.96e8 Km)^2)*(5.67051e-8)*((5407 K)^4))) / (((1.051-(1.051*0.07))*149597876600m)^2))</math>


'''Average Flux:''' '''Average Flux:'''
<math>f_p= \frac{( (1.22 \times 6.955 \times 10^8 )^2 ) \times (5.67051 \times 10^{-8}) \times (5407^4 K)} { 1.051 \times 149597876600 m)^2 }</math>

<math>(((1.22*6.96e8 Km)^2)*((5.67051e-8)*((5407 K)^4))) / ((1.051*149597876600m)^2))</math>


'''Apastron Flux:''' '''Apastron Flux:'''
<math>(((1.22*6.96e8 Km)^2)*((5.67051e-8)*((5407 K)^4))) /( ((1.051+(1.051*0.07))*149597876600m)^2)</math> <math>f_p= \frac{( (1.22 \times 6.955 \times 10^8 )^2 ) \times (5.67051 \times 10^{-8}) \times (5407^4 K)} { ( ( 1.051+ ( 1.051\times 0.07 ) ) \times 149597876600 m)^2 }</math>


---- ----

Revision as of 00:18, 9 June 2008

HD 108874
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
Distance106 ly
(30.6 pc)
Absolute magnitude (MV)3.72
Details
Mass1 M☉
Radius1.22 R☉
Luminosity? L☉
Temperature5407 K
Metallicity=+0.14
Rotation?
Age7.26 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

HD 108874 b
Orbital characteristics
Semi-major axis1.051 ± 0.02
Eccentricity0.07 ± 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 293 planets found so far (June/07) it has the most Earth-like insolation.








Using the following formulas, derived 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: f p = ( ( 1.22 × 6.955 × 10 8 ) 2 ) × ( 5.67051 × 10 − 8 ) × ( 5407 4 K ) ( ( 1.051 − ( 1.051 × 0.07 ) ) × 149597876600 m ) 2 {\displaystyle f_{p}={\frac {((1.22\times 6.955\times 10^{8})^{2})\times (5.67051\times 10^{-8})\times (5407^{4}K)}{((1.051-(1.051\times 0.07))\times 149597876600m)^{2}}}}

Average Flux: f p = ( ( 1.22 × 6.955 × 10 8 ) 2 ) × ( 5.67051 × 10 − 8 ) × ( 5407 4 K ) 1.051 × 149597876600 m ) 2 {\displaystyle f_{p}={\frac {((1.22\times 6.955\times 10^{8})^{2})\times (5.67051\times 10^{-8})\times (5407^{4}K)}{1.051\times 149597876600m)^{2}}}}

Apastron Flux: f p = ( ( 1.22 × 6.955 × 10 8 ) 2 ) × ( 5.67051 × 10 − 8 ) × ( 5407 4 K ) ( ( 1.051 + ( 1.051 × 0.07 ) ) × 149597876600 m ) 2 {\displaystyle f_{p}={\frac {((1.22\times 6.955\times 10^{8})^{2})\times (5.67051\times 10^{-8})\times (5407^{4}K)}{((1.051+(1.051\times 0.07))\times 149597876600m)^{2}}}}

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

HD 108874 c
Orbital characteristics
Semi-major axis2.68 ± 0.25
Eccentricity0.25 ± 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

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

Stub icon

This main-sequence-star-related article is a stub. You can help Misplaced Pages by expanding it.

Categories: