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Rare exoplanet 41 EP

K2-216 b

RA 11.4802° · Dec 6.3470° · exoplanet

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Score breakdown

· 4 badges
41 pts · Rare
Rare 50 pts → Epic
  • Denser than iron +18
  • Tidally locked +10
  • Super-Earth +8
  • Confirmed exoplanet +5
Total score 41

9 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Super-Earth · +8
  • Tidally locked · +10
  • Denser than iron · +18

Trivia

Hard to believe

  • Denser than iron. It is packed tighter than solid iron — whatever it is made of, it is not ordinary rock.

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. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.

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 12.4 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

density gcc
8.2
diameter km
22323.35
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
376.583
eccentricity
0
eq temp k
1103
host star teff
4503
inclination
86.9
insolation
248
mag
12.403
mass earth
8
name
K2-216 b
orbital period days
2.1748
radius earth
1.75
semi major au
0.028
spect
K5 V
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-216 b

K2-216 b is a rare exoplanet. It lies about 376.6 light-years from Earth, shines at apparent magnitude 12.4, has spectral type K5 V and has an equilibrium temperature near 1,103 K.

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 12.4, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-216 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 K2-216 b is a rare exoplanet

K2-216 b scores 41 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, Tidally locked and Denser than iron — 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.