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Rare exoplanet 49 EP

K2-156 b

RA 182.6997° · Dec -6.2944° · exoplanet

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Score breakdown

· 4 badges
49 pts · Rare
Rare 50 pts → Epic
  • Earth-sized +16
  • Lava world +14
  • Ultra-short period +14
  • Confirmed exoplanet +5
Total score 49

1 more point to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Earth-sized · +16
  • Lava world · +14
  • Ultra-short period · +14

Trivia

What makes it special

  • Earth-sized. Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.
  • Lava world. Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

Hard to believe

  • A year in a day. Its entire year is over in 19.5 hours. Birthdays here would come round faster than meals.

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 13.4 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.

Properties

density gcc
5.66
diameter km
14031.82
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
489.9189
eq temp k
1347
host star teff
4460
inclination
89.8
insolation
654.0363
mag
13.4
mass earth
1.37
name
K2-156 b
orbital period days
0.8131
radius earth
1.1
semi major au
0.0149
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-156 b

K2-156 b is a rare exoplanet. It lies about 489.9 light-years from Earth, shines at apparent magnitude 13.4, has an equilibrium temperature near 1,347 K and spans roughly 1.1 Earth radii.

Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.

How to see it

At apparent magnitude 13.4, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-156 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 K2-156 b is a rare exoplanet

K2-156 b scores 49 points on Spacedle's rarity scale, which places it in the rare tier. Another 1 point would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Earth-sized, Lava world and Ultra-short period — 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.