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Uncommon exoplanet 25 EP

HD 117207 b

RA 202.3369° · Dec -35.5713° · exoplanet

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Score breakdown

· 4 badges
25 pts · Uncommon
Uncommon 34 pts → Rare
  • Frozen world +8
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 25

9 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Frozen world · +8
  • Orbits a Sun-like star · +8

Trivia

What makes it special

  • Frozen world. A deep-frozen world, too far from its star's warmth for anything to stay liquid.

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.

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 7.3 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.
  • Best time of year. It stands highest in the middle of the night around April — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 1.9 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.53
diameter km
170933.08
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2004
dist ly
105.5268
eccentricity
0.157
eq temp k
147.2
host star teff
5732
inclination
76.6
insolation
0.0811
mag
7.26
mass earth
669.3466
name
HD 117207 b
orbital period days
2621.75
radius earth
13.4
semi major au
3.787
spect
G7 IV-V
sys num planets
1
sys num stars
1

About HD 117207 b

HD 117207 b is an uncommon exoplanet. It lies about 105.5 light-years from Earth, shines at apparent magnitude 7.26, has spectral type G7 IV-V and has an equilibrium temperature near 147 K.

A deep-frozen world, too far from its star's warmth for anything to stay liquid.

How to see it

At apparent magnitude 7.26, it is an easy target for binoculars.

Like any astronomical target, HD 117207 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 117207 b is an uncommon exoplanet

HD 117207 b scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Frozen world 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.