Exoplanet · mini-Neptune
HD 5278 b
HD 5278 b is a mini-Neptune orbiting the star HD 5278. Its year lasts 14.3 Earth days. It was discovered in 2021 by the Transit method.
| Host star | HD 5278 |
|---|---|
| Distance | 187.8 light-years (57.6 pc) |
| Orbital period | 14.3 days |
| Orbital radius | 0.12 AU |
| Eccentricity | 0.080 |
| Radius | 2.45 R⊕ · 0.219 R♃ |
| Mass | 7.8 M⊕ · 0.0245 M♃ |
| Density | 2.9 g/cm³ |
| Surface gravity | 1.3 × Earth |
| Equilibrium temperature | 943 K (670 °C) |
| Stellar flux received | 132 × Earth |
| Discovery method | Transit |
| Discovery year | 2021 |
| Discovered by | Transiting Exoplanet Survey Satellite (TESS) |
Habitable zone
Inside the inner edge of the habitable zone: it receives 132 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 5.3° across: 9.9 times the Sun as we see it from Earth.
In the sky
Too faint for the naked eye (magnitude 7.94); binoculars will find it. Visible from the whole Southern Hemisphere and north to latitude 6° N. South of latitude 6° S it never sets.
Light's journey
The light you see tonight set out around the year 1838. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 3.3 million years.
Planets in the same system
- HD 5278 c 40.9-day orbit · 4.49 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.