About TOI-1221 b
TOI-1221 b is an uncommon exoplanet. It lies about 451.4 light-years from Earth, shines at apparent magnitude 10.49, has an equilibrium temperature near 440 K and spans roughly 2.91 Earth radii.
About 2.9× the width of Earth.
Uncommon exoplanet 22 EP
TOI-1221 b
RA 107.9210° · Dec -65.5089° · exoplanet
Score breakdown
· 4 badgesUncommon 34 pts → Rare
- Orbits a Sun-like star +8
- Confirmed exoplanet +5
- Sub-Neptune +5
- Found by TESS +4
Total score 22
12 more points to reach Rare.
Badges
- Confirmed exoplanet · +5
- Sub-Neptune · +5
- Found by TESS · +4
- Orbits a Sun-like star · +8
Trivia
Sense of scale
- In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.
Find it in the sky
- How to spot it. At magnitude 10.5 you'll want a small backyard telescope.
- Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
- Best time of year. It stands highest in the middle of the night around January — that's when to go looking.
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 7.9 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 704.9 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 4514 years in a starship at a tenth of light speed.
Properties
- diameter km
- 37120.542
- discovery facility
- Transiting Exoplanet Survey Satellite (TESS)
- discovery method
- Transit
- discovery year
- 2023
- dist ly
- 451.4358
- eccentricity
- 0.21
- eq temp k
- 440
- host star teff
- 5592
- inclination
- 89.75
- insolation
- 6.06
- mag
- 10.494
- mass earth
- 1112.3994
- name
- TOI-1221 b
- orbital period days
- 91.6828
- radius earth
- 2.91
- semi major au
- 0.387
- sys num planets
- 1
- sys num stars
- 1
How to see it
At apparent magnitude 10.49, a small backyard telescope will bring it into view.
Like any astronomical target, TOI-1221 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Why TOI-1221 b is an uncommon exoplanet
TOI-1221 b scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 points would lift it into a rarer tier.
That score comes from 4 science badges — Confirmed exoplanet, Sub-Neptune, Found by TESS and Orbits a Sun-like star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.