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Rare exoplanet 44 EP

K2-278 b

RA 203.3019° · Dec -14.5041° · exoplanet

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Score breakdown

· 6 badges
44 pts · Rare
Rare 50 pts → Epic
  • Lava world +14
  • Tidally locked +10
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Sub-Neptune +5
  • Blasted by starlight +4
Total score 44

6 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Sub-Neptune · +5
  • Lava world · +14
  • Tidally locked · +10
  • Blasted by starlight · +4

Trivia

What makes it special

  • Lava world. Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

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.

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.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around April — 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
1.9
diameter km
38013.476
discovery facility
K2
discovery method
Transit
discovery year
2018
dist ly
2565.018
eq temp k
1711
host star teff
6747
insolation
1051.5587
mag
13.446
mass earth
9.17
name
K2-278 b
orbital period days
3.335
radius earth
2.98
semi major au
0.0488
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-278 b

K2-278 b is a rare exoplanet. It lies about 2,565 light-years from Earth, shines at apparent magnitude 13.45, has an equilibrium temperature near 1,711 K and spans roughly 2.98 Earth radii.

Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

How to see it

At apparent magnitude 13.45, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-278 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 K2-278 b is a rare exoplanet

K2-278 b scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Sub-Neptune, Lava world, Tidally locked and Blasted by starlight — 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.