← Back to dex
Epic exoplanet 50 EP

Kepler-221 b

RA 296.6547° · Dec 46.8352° · exoplanet

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 7 badges
50 pts · Epic
Epic 78 pts → Anomaly
  • Puffy low-density world +12
  • Tidally locked +10
  • Super-Earth +8
  • Distant (over 1,000 light-years) +6
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Found by Kepler +3
Total score 50

28 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Super-Earth · +8
  • Tidally locked · +10
  • Puffy low-density world · +12
  • Multi-planet system · +6
  • Found by Kepler · +3

Trivia

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.
  • Crowded system. One of at least 4 planets orbiting its star.

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 14 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around July — that's when to go looking.

Properties

density gcc
0.19
diameter km
21813.102
discovery facility
Kepler
discovery method
Transit
discovery year
2014
dist ly
1256.454
eccentricity
0
eq temp k
1090
host star teff
5243
inclination
85.58
insolation
308.885
mag
13.97
mass earth
5.9558
name
Kepler-221 b
orbital period days
2.7959
radius earth
1.71
semi major au
0.037
sys num planets
4
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About Kepler-221 b

Kepler-221 b is an epic exoplanet. It lies about 1,256.5 light-years from Earth, shines at apparent magnitude 13.97, has an equilibrium temperature near 1,090 K and spans roughly 1.71 Earth radii.

It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.

How to see it

At apparent magnitude 13.97, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, Kepler-221 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 Kepler-221 b is an epic exoplanet

Kepler-221 b scores 50 points on Spacedle's rarity scale, which places it in the epic tier. Another 28 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Super-Earth, Tidally locked, Puffy low-density world, Multi-planet system and Found by Kepler — 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.