Confirmed exoplanet · Database record + computed analysis
TOI-1221 b
A confirmed world orbiting TOI-1221, 451.4 light-years away.
A sub-Neptune
2.91 Earth radii, likely a rocky core under a thick gas or steam envelope rather than a walkable surface. With 1112.4 Earth masses packed into that size, its density points to rock and iron rather than gas.
The orbit
Its year takes 92 Earth days (0.3 Earth years).
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 167 °C. Above water's boiling point. It receives 6.1 times the starlight Earth gets.
Its sun
Its star is Sun-like (5,592 K; the Sun is 5,772 K).
How far is that, really?
At 451 light-years, tonight's light from this system left it around the year 1574. A Voyager-speed probe would need roughly 7,987,078 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.