Exoplanet
The first exoplanet discovered orbiting a Sun-like star, a 'hot Jupiter' whose discovery launched modern exoplanet science.
| Type | Exoplanet |
|---|---|
| Orbits | 51 Pegasi |
| Distance from Earth | 50.9 ly |
| Diameter | 179,662 km |
| Mass | 1.16 × 10²⁷ kg |
| Temperature | 1,011°C |
| Orbital period | 4 days |
| Apparent magnitude | 5.49 |
| Hemisphere | Northern |
| Discovered | 1995 |
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 179,662 km across, 51 Pegasi b is 14 times the diameter of Earth.
Its mass is 194 times the mass of Earth.
A single orbit takes 4.2 days.
The light reaching us from 51 Pegasi b tonight left it around 51 years ago.
An average temperature of 1,284 K works out at 1,011 degrees Celsius, warmer than the 15 degrees Earth averages.
It has been on record since 1995.
Play today's Cosmodle