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Epic exoplanet 53 EP

GJ 1148 b

RA 175.4326° · Dec 42.7516° · exoplanet

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Score breakdown

· 5 badges
53 pts · Epic
Epic 78 pts → Anomaly
  • In the habitable zone +30
  • Orbits a red dwarf +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 53

25 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Multi-planet system · +6
  • 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.

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

  • 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. 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 2 planets orbiting its star.

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 11.9 you'll want a small backyard telescope.

Properties

density gcc
0.315
diameter km
151798.78
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2010
dist ly
35.9238
eccentricity
0.38
eq temp k
232.94
habitable zone
yes
host star teff
3287
insolation
0.4906
mag
11.939
mass earth
96.7
name
GJ 1148 b
orbital period days
41.38
radius earth
11.9
semi major au
0.166
spect
M5
sys num planets
2
sys num stars
1

About GJ 1148 b

GJ 1148 b is an epic exoplanet. It lies about 35.9 light-years from Earth, shines at apparent magnitude 11.94, has spectral type M5 and has an equilibrium temperature near 233 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 11.94, a small backyard telescope will bring it into view.

Like any astronomical target, GJ 1148 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 GJ 1148 b is an epic exoplanet

GJ 1148 b scores 53 points on Spacedle's rarity scale, which places it in the epic tier. Another 25 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, In the habitable zone, Gas giant, Multi-planet system 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.