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Uncommon exoplanet 25 EP

K2-281 b

RA 16.2275° · Dec 7.2692° · exoplanet

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Score breakdown

· 4 badges
25 pts · Uncommon
Uncommon 34 pts → Rare
  • Tidally locked +10
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 25

9 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Gas giant · +4
  • Tidally locked · +10

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.

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 15 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. Impossible with our current technology — and the next millennium of it.

Properties

density gcc
0.511
diameter km
104345.716
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
1494.2478
eq temp k
665
host star teff
4812
insolation
37.7384
mag
15.048
mass earth
50.9
name
K2-281 b
orbital period days
8.6877
radius earth
8.18
semi major au
0.0773
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-281 b

K2-281 b is an uncommon exoplanet. It lies about 1,494.2 light-years from Earth, shines at apparent magnitude 15.05, has an equilibrium temperature near 665 K and spans roughly 8.18 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 15.05, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-281 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 K2-281 b is an uncommon exoplanet

K2-281 b scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Gas giant 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.