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Epic exoplanet 60 EP

HN Lib b

RA 218.5685° · Dec -12.5170° · exoplanet

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Score breakdown

· 5 badges
60 pts · Epic
Epic 78 pts → Anomaly
  • In the habitable zone +30
  • Nearby (<25 ly) +12
  • Orbits a red dwarf +8
  • Confirmed exoplanet +5
  • Sub-Neptune +5
Total score 60

18 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Nearby (<25 ly) · +12
  • In the habitable zone · +30
  • Sub-Neptune · +5
  • Orbits a red dwarf · +8

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.

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Too light to be solid rock and too heavy to be all gas: most likely a deep global ocean or a thick steamy envelope over a rocky core.
  • 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.

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 11.3 you'll want a small backyard telescope.
  • 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 April — that's when to go looking.

Properties

density gcc
2.82
diameter km
28063.64
discovery facility
Calar Alto Observatory
discovery method
Radial Velocity
discovery year
2023
dist ly
20.3666
eccentricity
0.079
eq temp k
234.4
habitable zone
yes
host star teff
3347
insolation
0.503
mag
11.311
mass earth
5.46
name
HN Lib b
orbital period days
36.116
radius earth
2.2
semi major au
0.1417
spect
M4.0 V
sys num planets
1
sys num stars
1

Nearby objects

About HN Lib b

HN Lib b is an epic exoplanet. It lies about 20.4 light-years from Earth, shines at apparent magnitude 11.31, has spectral type M4.0 V and has an equilibrium temperature near 234 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 11.31, a small backyard telescope will bring it into view.

Like any astronomical target, HN Lib 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 HN Lib b is an epic exoplanet

HN Lib b scores 60 points on Spacedle's rarity scale, which places it in the epic tier. Another 18 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Nearby (<25 ly), In the habitable zone, Sub-Neptune and Orbits a red dwarf — 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.