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Uncommon exoplanet 33 EP

HD 18143 c

RA 43.9140° · Dec 26.8724° · exoplanet

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Score breakdown

· 5 badges
33 pts · Uncommon
Uncommon 34 pts → Rare
  • Long-period world +10
  • Frozen world +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 33

1 more point to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Frozen world · +8
  • Long-period world · +10
  • Multi-planet system · +6

Trivia

What makes it special

  • Frozen world. A deep-frozen world, too far from its star's warmth for anything to stay liquid.

Hard to believe

  • Denser than iron. It is packed tighter than solid iron — whatever it is made of, it is not ordinary rock.

What it actually is

  • What it is made of. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.
  • Crowded system. One of at least 2 planets orbiting its star.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • 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
8.94
diameter km
159452.5
discovery facility
Multiple Observatories
discovery method
Radial Velocity
discovery year
2022
dist ly
73.4644
eccentricity
0.194
eq temp k
54.55
host star teff
5078
inclination
35.98
insolation
0.0016
mag
7.518
mass earth
3177.6484
name
HD 18143 c
orbital period days
28982.4176
radius earth
12.5
semi major au
17.53
spect
K2
sys num planets
2
sys num stars
1

About HD 18143 c

HD 18143 c is an uncommon exoplanet. It lies about 73.5 light-years from Earth, shines at apparent magnitude 7.52, has spectral type K2 and has an equilibrium temperature near 55 K.

A deep-frozen world, too far from its star's warmth for anything to stay liquid.

How to see it

At apparent magnitude 7.52, it is an easy target for binoculars.

Like any astronomical target, HD 18143 c 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 HD 18143 c is an uncommon exoplanet

HD 18143 c scores 33 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Frozen world, Long-period world and Multi-planet system — 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.