Exoplanet · gas giant
alf Ari b
alf Ari b is a gas giant orbiting the star Hamal. Its year lasts 381 Earth days. It was discovered in 2010 by the Radial Velocity method.
| Host star | Hamal |
|---|---|
| Distance | 65.9 light-years (20.2 pc) |
| Orbital period | 381 days |
| Orbital radius | 1.2 AU |
| Eccentricity | 0.250 |
| Radius | 13.4 R⊕ · 1.2 R♃ |
| Mass (minimum) | 572 M⊕ · 1.8 M♃ |
| Density | 1.31 g/cm³ |
| Equilibrium temperature | 747 K (474 °C) |
| Stellar flux received | 59.7 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2010 |
| Discovered by | Bohyunsan Optical Astronomical Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 59.7 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 6.2° across: 12 times the Sun as we see it from Earth.
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 2.01). Visible from the whole Northern Hemisphere and south to latitude 67° S. North of latitude 67° N it never sets. It stands highest at midnight in October, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1960. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.2 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.