Exoplanet · Neptune-like planet
TOI-6478 b
TOI-6478 b is a Neptune-like planet orbiting the star TOI-6478. Its year lasts 34 Earth days. It was discovered in 2025 by the Transit method.
| Host star | TOI-6478 |
|---|---|
| Distance | 125.9 light-years (38.6 pc) |
| Orbital period | 34 days |
| Orbital radius | 0.114 AU |
| Radius | 4.6 R⊕ · 0.41 R♃ |
| Mass | 19.2 M⊕ · 0.0604 M♃ (estimated from the radius) |
| Density | 1.08 g/cm³ |
| Equilibrium temperature | 204 K (-69 °C) |
| Stellar flux received | 3.00 × 10⁻⁴ × Earth |
| Discovery method | Transit |
| Discovery year | 2025 |
| Discovered by | Transiting Exoplanet Survey Satellite (TESS) |
Habitable zone
Beyond the habitable zone: it receives only %0.03 of the light the Earth does, a frozen world.
Its star in the sky
In the planet's sky its star is a disc 1.1° across: 2.1 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 15.65. Visible from the whole Southern Hemisphere and north to latitude 74° N. South of latitude 74° S it never sets. It stands highest at midnight in February, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1900. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.2 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.