Confirmed exoplanet · Database record + computed analysis
HD 5278 c
A confirmed world orbiting HD 5278, 187.8 light-years away.
A Neptune-class world
4.49 Earth radii, in the ice-giant size range. At only 18.4 Earth masses for that size, it must be substantially gas or volatile ices: puffy, not rocky.
The orbit
Its year, one full orbit, takes just 40.9 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 392 °C. Above water's boiling point. It receives 32.7 times the starlight Earth gets.
Its sun
Its star is hotter than the Sun (6,203 K, F V), burning brighter and faster. It shares the system with 1 other known planet.
How far is that, really?
At 188 light-years, tonight's light from this system left it around the year 1838. A Voyager-speed probe would need roughly 3,322,949 years to get there.
How we found it
It was found by the radial-velocity method: the planet's gravity swings its star in a small circle, and that wobble shows up as a rhythmic Doppler shift in the starlight. The wobble's size gives the planet's minimum mass. The discovery was announced in 2021 from Paranal Observatory.
Everything above is computed from the archive’s measured values for this planet. Where a quantity is missing, the statement is omitted rather than guessed.
About this record
The measured values come from the NASA Exoplanet Archive, and any missing value has not been determined yet; the Atlas never fills gaps with guesses. More standout worlds: Proxima b, TRAPPIST-1e, K2-18 b, 55 Cancri e, and the detection methods that found them all.