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Common exoplanet 15 EP

GJ 328 c

RA 133.7820° · Dec 1.5420° · exoplanet

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Score breakdown

· 3 badges
15 pts · Common
Common 22 pts → Uncommon
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Neptune-like +4
Total score 15

7 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Neptune-like · +4
  • Multi-planet system · +6

Trivia

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.
  • 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 10 you'll want a small backyard telescope.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around February — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

density gcc
0.993
diameter km
62632.942
discovery facility
Roque de los Muchachos Observatory
discovery method
Radial Velocity
discovery year
2023
dist ly
66.9487
eq temp k
184.01
host star teff
3897
insolation
0.1927
mag
9.99
mass earth
21.4
name
GJ 328 c
orbital period days
241.8
radius earth
4.91
semi major au
0.657
spect
M0.0
sys num planets
2
sys num stars
1

Nearby objects

About GJ 328 c

GJ 328 c is a common exoplanet. It lies about 66.9 light-years from Earth, shines at apparent magnitude 9.99, has spectral type M0.0 and has an equilibrium temperature near 184 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 9.99, a small backyard telescope will bring it into view.

Like any astronomical target, GJ 328 c 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 328 c is a common exoplanet

GJ 328 c scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Neptune-like and Multi-planet system — 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.