Exoplanet · gas giant
HD 187123 b
HD 187123 b is a gas giant orbiting the star HD 187123. Its year lasts 3.1 Earth days. It was discovered in 1998 by the Radial Velocity method.
| Host star | HD 187123 |
|---|---|
| Distance | 149.9 light-years (46.0 pc) |
| Orbital period | 3.1 days |
| Orbital radius | 0.0426 AU |
| Eccentricity | 0.010 |
| Radius | 14.2 R⊕ · 1.27 R♃ |
| Mass (minimum) | 166 M⊕ · 0.523 M♃ |
| Density | 0.319 g/cm³ |
| Equilibrium temperature | 1,451 K (1,178 °C) |
| Stellar flux received | 738 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 1998 |
| Discovered by | W. M. Keck Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 738 times the light the Earth does, too hot to keep liquid water on its surface.
Its star in the sky
In the planet's sky its star is a disc 14° across: 27 times the Sun as we see it from Earth.
In the sky
Too faint for the naked eye (magnitude 7.83); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 56° S. North of latitude 56° N it never sets. It stands highest at midnight in July, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1876. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.7 million years.
Planets in the same system
- HD 187123 c 3,810-day orbit · 13.2 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.