Confirmed exoplanet · Database record + computed analysis
HIP 9618 b
A confirmed world orbiting HIP 9618, 220.3 light-years away.
A sub-Neptune
3.83 Earth radii, likely a rocky core under a thick gas or steam envelope rather than a walkable surface. At only 8.3 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 20.8 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 368 °C. Above water's boiling point. It receives 40.3 times the starlight Earth gets.
Its sun
Its star is Sun-like (5,649 K; the Sun is 5,772 K). It shares the system with 1 other known planet.
How far is that, really?
At 220 light-years, tonight's light from this system left it around the year 1805. A Voyager-speed probe would need roughly 3,897,881 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 2023 from Transiting Exoplanet Survey Satellite (TESS).
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.