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Rare exoplanet 35 EP

47 UMa c

RA 164.8648° · Dec 40.4305° · exoplanet

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Score breakdown

· 5 badges
35 pts · Rare
Rare 50 pts → Epic
  • Its star is visible to the naked eye +12
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 35

15 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Multi-planet system · +6
  • Its star is visible to the naked eye · +12
  • Orbits a Sun-like star · +8

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 3 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 5 you can see it with your own eyes from a dark site.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Could we get there?

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

Properties

density gcc
0.329
diameter km
181138.04
discovery facility
Lick Observatory
discovery method
Radial Velocity
discovery year
2001
dist ly
44.9988
eccentricity
0.098
eq temp k
164.38
host star teff
5872
insolation
0.1217
mag
5.0335
mass earth
171.621
name
47 UMa c
orbital period days
2391
radius earth
14.2
semi major au
3.6
spect
G0V
sys num planets
3
sys num stars
1

About 47 UMa c

47 UMa c is a rare exoplanet. It lies about 45 light-years from Earth, shines at apparent magnitude 5.03, has spectral type G0V and has an equilibrium temperature near 164 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 5.03, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 47 UMa 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 47 UMa c is a rare exoplanet

47 UMa c scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Multi-planet system, Its star is visible to the naked eye 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.