Exoplanet
One of the first exoplanets ever directly photographed, part of a system with four giant planets imaged in orbit around their star.
| Type | Exoplanet |
|---|---|
| Orbits | HR 8799 |
| Distance from Earth | 133 ly |
| Diameter | 168,000 km |
| Mass | 1.14 × 10²⁸ kg |
| Temperature | 927°C |
| Orbital period | 175,000 days |
| Apparent magnitude | 5.96 |
| Hemisphere | Northern |
| Discovered | 2008 |
Every exoplanet here was found indirectly, by the wobble or the dimming it causes in its own star, since none is close enough to photograph in real detail.
At 168,000 km across, HR 8799 b is 13 times the diameter of Earth.
Its mass is 1,909 times the mass of Earth.
A single orbit takes 479 years.
The light reaching us from HR 8799 b tonight left it around 133 years ago.
An average temperature of 1,200 K works out at 927 degrees Celsius, warmer than the 15 degrees Earth averages.
It has been on record since 2008.
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