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Uncommon exoplanet 23 EP

K2-203 b

RA 12.7737° · Dec -1.1959° · exoplanet

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Score breakdown

· 3 badges
23 pts · Uncommon
Uncommon 34 pts → Rare
  • Tidally locked +10
  • Super-Earth +8
  • Confirmed exoplanet +5
Total score 23

11 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Super-Earth · +8
  • Tidally locked · +10

Trivia

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.

Getting there

  • Aboard Voyager 1. ≈ 9.5 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
5.8
diameter km
16142.8935
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
541.8984
eccentricity
0.23
eq temp k
738.4
host star teff
5026
inclination
89.12
insolation
49.6336
mag
12.391
mass earth
2.14
name
K2-203 b
orbital period days
9.6952
radius earth
1.2655
semi major au
0.0824
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-203 b

K2-203 b is an uncommon exoplanet. It lies about 541.9 light-years from Earth, shines at apparent magnitude 12.39, has an equilibrium temperature near 738 K and spans roughly 1.27 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 12.39, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-203 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 K2-203 b is an uncommon exoplanet

K2-203 b scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Super-Earth and Tidally locked — 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.