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Uncommon exoplanet 29 EP

HD 204941 b

RA 323.0967° · Dec -20.9580° · exoplanet

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Score breakdown

· 4 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Two suns in its sky +12
  • Frozen world +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 29

5 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Frozen world · +8
  • Two suns in its sky · +12

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

  • 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

  • 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. 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 8.4 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • 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 August — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

density gcc
0.39
diameter km
128837.62
discovery facility
La Silla Observatory
discovery method
Radial Velocity
discovery year
2011
dist ly
93.6606
eccentricity
0.37
eq temp k
134.04
host star teff
5026
insolation
0.0477
mag
8.45
mass earth
73.1009
multi star system
yes
name
HD 204941 b
orbital period days
1733
radius earth
10.1
semi major au
2.55
spect
K1/2V
sys num planets
1
sys num stars
2

Nearby objects

About HD 204941 b

HD 204941 b is an uncommon exoplanet. It lies about 93.7 light-years from Earth, shines at apparent magnitude 8.45, has spectral type K1/2V and has an equilibrium temperature near 134 K.

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

How to see it

At apparent magnitude 8.45, it is an easy target for binoculars.

Like any astronomical target, HD 204941 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 HD 204941 b is an uncommon exoplanet

HD 204941 b scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Frozen world and Two suns in its sky — 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.