Iolaus
HAT-P-42 b
IAU name «Iolaus» — Greece, 2019 contest
📋 A written introduction is coming — for now this page shows official values only.
Planet
- Host star
- HAT-P-42
- Distance from Earth
- 405.238 pc (≈ 1,321.7 light-years)
- NASA planet type
- Gas Giant
- Radius (Earth = 1)
- 14.348
- Mass (Earth = 1)
- 331.801
- Orbital period
- 4.6419 days
- Semi-major axis
- 0.0575 AU
- Eccentricity
- 0
- Equilibrium temperature
- 1,428 K
- Discovery method
- Transit
- Discovery year
- 2,012
- Discovery facility
- HATNet
- Host temperature
- 5,743 K
- Host radius (Sun = 1)
- 1.53
- Host mass (Sun = 1)
- 1.178
- Host brightness
- 12.125 mag
Source:NASA Exoplanet Archive (Caltech/IPAC) · checked 2026-11-02 ↗NASA Science · checked 2026-11-02 ↗
Related
Host star
In everyday life
- Light from this object takes about 1,322 years to reach Earth — the light you see tonight left around AD 704 (official distance ÷ speed of light).
- Its radius is about 14 times Earth's (NASA Exoplanet Archive).
- One orbit takes about 4.6 Earth days — that is this planet's year.
Worked out from this object's official values.