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Uncommon exoplanet 24 EP

K2-158 b

RA 179.9397° · Dec -5.7217° · exoplanet

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Score breakdown

· 4 badges
24 pts · Uncommon
Uncommon 34 pts → Rare
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Sub-Neptune +5
Total score 24

10 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Sub-Neptune · +5
  • Multi-planet system · +6
  • Orbits a Sun-like star · +8

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. Too light to be solid rock and too heavy to be all gas: most likely a deep global ocean or a thick steamy envelope over a rocky core.
  • Crowded system. One of at least 2 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 11.8 you'll want a small backyard telescope.
  • 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 March — that's when to go looking.

Could we get there?

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

Properties

density gcc
2.23
diameter km
33676.368
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
643.5025
eq temp k
794
host star teff
5503
inclination
88.4045
insolation
87.3327
mag
11.774
mass earth
7.46
name
K2-158 b
orbital period days
10.0605
radius earth
2.64
semi major au
0.0887
sys num planets
2
sys num stars
1

About K2-158 b

K2-158 b is an uncommon exoplanet. It lies about 643.5 light-years from Earth, shines at apparent magnitude 11.77, has an equilibrium temperature near 794 K and spans roughly 2.64 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 11.77, a small backyard telescope will bring it into view.

Like any astronomical target, K2-158 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 K2-158 b is an uncommon exoplanet

K2-158 b scores 24 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 10 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Sub-Neptune, Multi-planet system 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.