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Uncommon exoplanet 26 EP

HD 165131 b

RA 271.3444° · Dec -21.6737° · 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

  • 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.

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 8.4 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 June — 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. ≈ 3.3 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
18.4
diameter km
154350.02
discovery facility
Multiple Facilities
discovery method
Radial Velocity
discovery year
2023
dist ly
187.2993
eccentricity
0.6708
eq temp k
155.2
host star teff
5870
inclination
70
insolation
0.0967
mag
8.42
mass earth
5943.3912
name
HD 165131 b
orbital period days
2342.6
radius earth
12.1
semi major au
3.54
spect
G3/5 V
sys num planets
1
sys num stars
1

About HD 165131 b

HD 165131 b is an uncommon exoplanet. It lies about 187.3 light-years from Earth, shines at apparent magnitude 8.42, has spectral type G3/5 V and has an equilibrium temperature near 155 K.

Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.

How to see it

At apparent magnitude 8.42, it is an easy target for binoculars.

Like any astronomical target, HD 165131 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 165131 b is an uncommon exoplanet

HD 165131 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.