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Rare exoplanet 41 EP

K2-85 b

RA 59.4648° · Dec 18.4650° · exoplanet

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Score breakdown

· 4 badges
41 pts · Rare
Rare 50 pts → Epic
  • Lava world +14
  • Ultra-short period +14
  • Super-Earth +8
  • Confirmed exoplanet +5
Total score 41

9 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Super-Earth · +8
  • Lava world · +14
  • Ultra-short period · +14

Trivia

What makes it special

  • 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 16.4 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 12.4 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around November — that's when to go looking.

Properties

density gcc
5.9
diameter km
17858.68
discovery facility
K2
discovery method
Transit
discovery year
2016
dist ly
317.082
eccentricity
0.24
eq temp k
1355
host star teff
4232
inclination
80.21
insolation
800
mag
12.416
mass earth
3.2
name
K2-85 b
orbital period days
0.6845
radius earth
1.4
semi major au
0.013
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About K2-85 b

K2-85 b is a rare exoplanet. It lies about 317.1 light-years from Earth, shines at apparent magnitude 12.42, has an equilibrium temperature near 1,355 K and spans roughly 1.4 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 12.42, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-85 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 K2-85 b is a rare exoplanet

K2-85 b scores 41 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, 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.