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examiner.com/article/the-nature-of-the-kepler-47-system
http://www.openexoplanetcatalogue.com/system.html?id=Kepler-47(AB)%20b
On Wednesday, astronomers announced the discovery of two planets orbiting a binary star system known as Kepler-47. The star is 1,500 parsecs away from Earth, and is the first binary star system that has been found to have more than one planet. The two planets were discovered by NASA's Kepler space telescope, which has spotted 77 exoplanets and 2,321 exoplanet candidates since it was launched in March 2009.
Kepler-47 is in the constellation Cygnus. The two stars are known as Kepler-47A and Kepler-47B, and they orbit each other every 7.45 Earth days.
Kepler-47A has 1.043±0.055 times the mass of the Sun and 0.964±0.017 times the radius of the Sun. Its mean surface temperature is estimated to be 5636±100 K, while the mean surface temperature of the Sun is 5778 K. The spectral classification of Kepler-47A is G6V, which is slightly dimmer and redder than the G2V spectral classification of the Sun.
Kepler-47B has 0.362±0.013 times the mass of the Sun and 0.3506±0.0063 times the radius of the Sun. Its mean surface temperature is estimated to be 3357±100 K. The spectral classification of Kepler-47B is M4V, making it a red dwarf star.
| Star | Mass (sol) |
Radius (sol) |
Effective Temperatre(K) |
Mass (Mj) |
Radius (Mj) |
Semi-Major Axis (AU) |
Irradiance (W/m2) |
Irradiance (% of Sol) |
Irradiance (% Total) |
Effective Temperature (°C) |
|---|---|---|---|---|---|---|---|---|---|---|
| Kepler-47A | 1.043±0.055 | 0.964±0.017 | 5636±100 K | |||||||
| Kepler-47B | 0.362±0.013 | 0.3506±0.0063 | 3357±100 K | |||||||
| Kepler-47A-b | 2.7 | 0.265 | 0.2956±0.0047 | 13152.09 | 962.76% | |||||
| Kepler-47B-b | 2.7 | 0.265 | 0.2956±0.0047 | 218.97 | 16.03% | 978.79% | 175.85 | |||
| Kepler-47A-c | 17 | 0.410 | 0.989±0.016 | 1174.93 | 86.01% | |||||
| Kepler-47B-c | 17 | 0.410 | 0.989±0.016 | 19.56 | 1.43% | 87.44% | -28.15 | |||
| Earth/Sun | 1 | 1 | 5778 | 0.00315 | 0.0892 | 1 | 1366.08 | 100% | -18 |
=((((695500000)*0.964)^2)*(0.0000000567051)*(5636^4))/(149597870690*0.989)^2 = 13152.09 W/m2
Lede states there are "at least three planets" then goes on to talk about "the two planets". Inconsistency is obvious. Qemist (talk) 06:31, 26 April 2014 (UTC)Reply
Why is the surface gravity of Kepler-47B bigger than that of Kepler-47A, while the former is less massive? Aminabzz (talk) 17:34, 12 May 2023 (UTC)Reply
