Confirmed exoplanet · Database record + computed analysis
K2-403 b
A confirmed world orbiting K2-403, 804.3 light-years away.
A Neptune-class world
5.33 Earth radii, in the ice-giant size range. At only 24.6 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 33.6 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 676 °C. Hotter than Venus's surface. It receives 134.9 times the starlight Earth gets.
Its sun
Its star is Sun-like (5,511 K, G4; the Sun is 5,772 K).
How far is that, really?
At 804 light-years, tonight's light from this system left it around the year 1221. A Voyager-speed probe would need roughly 14,230,123 years to get there.
How we found it
It was found by the transit method: the planet crosses its star's face on schedule, dimming it by a tiny, repeating fraction. The dip's depth gives the planet's size. The discovery was announced in 2022 from K2.
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.