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Uncommon exoplanet 26 EP

HD 211810 b

RA 334.5287° · Dec 61.1350° · exoplanet

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Score breakdown

· 4 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Eccentric orbit +9
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 26

8 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Eccentric orbit · +9
  • Orbits a Sun-like star · +8

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

  • 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 8.6 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • 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.

Getting there

  • Aboard Voyager 1. ≈ 3.7 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
0.426
diameter km
178586.8
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2018
dist ly
210.8119
eccentricity
0.68
eq temp k
177.77
host star teff
5652
insolation
0.1665
mag
8.59
mass earth
212.9461
name
HD 211810 b
orbital period days
1558
radius earth
14
semi major au
2.656
spect
G5
sys num planets
1
sys num stars
1

About HD 211810 b

HD 211810 b is an uncommon exoplanet. It lies about 210.8 light-years from Earth, shines at apparent magnitude 8.59, has spectral type G5 and has an equilibrium temperature near 178 K.

Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

How to see it

At apparent magnitude 8.59, it is an easy target for binoculars.

Like any astronomical target, HD 211810 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 211810 b is an uncommon exoplanet

HD 211810 b scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Eccentric orbit and Orbits a Sun-like star — 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.