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Uncommon exoplanet 27 EP

HD 222155 b

RA 354.5026° · Dec 48.9960° · exoplanet

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Score breakdown

· 4 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Long-period world +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 27

7 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Long-period world · +10
  • Orbits a Sun-like star · +8

Trivia

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 7.1 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 September — 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. ≈ 2.9 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 257.7 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

density gcc
1.33
diameter km
170933.08
discovery facility
Haute-Provence Observatory
discovery method
Radial Velocity
discovery year
2011
dist ly
165.0604
eccentricity
0.16
eq temp k
164.93
host star teff
5701
inclination
68
insolation
0.1222
mag
7.1172
mass earth
581.626
name
HD 222155 b
orbital period days
3999
radius earth
13.4
semi major au
5.14
spect
G2 V
sys num planets
1
sys num stars
1

About HD 222155 b

HD 222155 b is an uncommon exoplanet. It lies about 165.1 light-years from Earth, shines at apparent magnitude 7.12, has spectral type G2 V and has an equilibrium temperature near 165 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 7.12, it is an easy target for binoculars.

Like any astronomical target, HD 222155 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 222155 b is an uncommon exoplanet

HD 222155 b scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Long-period world 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.