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Rare exoplanet 33 EP

HD 217107 c

RA 344.5647° · Dec -2.3954° · exoplanet

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Score breakdown

· 5 badges
33 pts · Rare
Rare 46 pts → Epic
  • Long-period world +10
  • Frozen world +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 33

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Frozen world · +8
  • Long-period world · +10
  • Multi-planet system · +6

Trivia

What makes it special

  • Frozen world. A deep-frozen world far from its star's warmth.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 1.1 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 102.2 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 654 years in a starship at a tenth of light speed.
  • Distance. 65.4 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1961.

Saying hello

  • Say hello. A radio message and its reply would take 131 years round-trip.

Standing on it

  • A year here. A full year lasts about 14.1 Earth years.

By the numbers

  • Size. About 12.9× the width of Earth.
  • Volume. About 2147 Earths could fit inside it.
  • Mass. Roughly 1389× Earth's mass — about 4.4 Jupiters.
  • Your weight. You'd weigh about 8.3× your Earth weight standing here.
  • Temperature. A frigid -150°C — colder than dry ice.

How we found it

  • Discovery. Found by Lick Observatory using the radial velocity method.

Cosmic context

  • Crowded system. One of at least 2 planets orbiting its star.

Properties

density gcc
3.56
discovery facility
Lick Observatory
discovery method
Radial Velocity
dist ly
65.4331
eccentricity
0.3918
eq temp k
123.27
insolation
0.0357
mass earth
1388.9101
name
HD 217107 c
orbital period days
5138.7
radius earth
12.9
sys num planets
2

About HD 217107 c

HD 217107 c is a rare exoplanet. It lies about 65.4 light-years from Earth, has an equilibrium temperature near 123 K, spans roughly 12.9 Earth radii and weighs about 1,388.91 Earth masses.

A deep-frozen world far from its star's warmth.

How to see it

Like any astronomical target, HD 217107 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 HD 217107 c is a rare exoplanet

HD 217107 c scores 33 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Frozen world, Long-period world 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.

spacedle A daily roll through the real universe. © 2026 spacedle. Buy me a coffee

Sky imagery and survey data courtesy of Aladin Lite & CDS, Strasbourg. Object data from the NASA Exoplanet Archive, JPL Small-Body Database, and the ATNF Pulsar Catalogue.