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Epic exoplanet 65 EP

HD 133131 A b

RA 225.8985° · Dec -27.8431° · exoplanet

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Score breakdown

· 6 badges
65 pts · Epic
Epic 78 pts → Anomaly
  • In the habitable zone +30
  • Two suns in its sky +12
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 65

13 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Multi-planet system · +6
  • Orbits a Sun-like star · +8
  • Two suns in its sky · +12

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

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.
  • What the zone means. The habitable zone is only about temperature: it is the band where liquid water could survive on a surface. It is a promising address, not evidence of anything living.
  • Crowded system. One of at least 3 planets orbiting its star.

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 7.7 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.

Properties

density gcc
0.986
diameter km
173484.32
discovery facility
Las Campanas Observatory
discovery method
Radial Velocity
discovery year
2016
dist ly
167.8842
eccentricity
0.33
eq temp k
227.72
habitable zone
yes
host star teff
5799
insolation
0.4642
mag
7.66
mass earth
451.3186
multi star system
yes
name
HD 133131 A b
orbital period days
649
radius earth
13.6
semi major au
1.44
spect
G2 V
sys num planets
3
sys num stars
2

Nearby objects

About HD 133131 A b

HD 133131 A b is an epic exoplanet. It lies about 167.9 light-years from Earth, shines at apparent magnitude 7.66, has spectral type G2 V and has an equilibrium temperature near 228 K.

Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

How to see it

At apparent magnitude 7.66, it is an easy target for binoculars.

Like any astronomical target, HD 133131 A 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 133131 A b is an epic exoplanet

HD 133131 A b scores 65 points on Spacedle's rarity scale, which places it in the epic tier. Another 13 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, In the habitable zone, Gas giant, Multi-planet system, Orbits a Sun-like star 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.