Rare exoplanet 33 EP

HD 187123 c

RA 296.7429° · Dec 34.4190° · 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. ≈ 2.6 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 234 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 1499 years in a starship at a tenth of light speed.
Distance. 150 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1876.

Saying hello

Say hello. A radio message and its reply would take 300 years round-trip.

Standing on it

A year here. A full year lasts about 10.4 Earth years.

By the numbers

Size. About 13.2× the width of Earth.
Volume. About 2300 Earths could fit inside it.
Mass. Roughly 912× Earth's mass — about 2.9 Jupiters.
Your weight. You'd weigh about 5.2× your Earth weight standing here.
Temperature. A frigid -138°C — colder than dry ice.

How we found it

Discovery. Found by W. M. Keck Observatory using the radial velocity method.

Cosmic context

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

Properties

density gcc: 2.18
discovery facility: W. M. Keck Observatory
discovery method: Radial Velocity
dist ly: 149.8843
eccentricity: 0.252
eq temp k: 135.42
insolation: 0.056
mass earth: 912.1675
name: HD 187123 c
orbital period days: 3810
radius earth: 13.2
sys num planets: 2

About HD 187123 c

HD 187123 c is a rare exoplanet. It lies about 149.9 light-years from Earth, has an equilibrium temperature near 135 K, spans roughly 13.2 Earth radii and weighs about 912.17 Earth masses.

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

How to see it

Like any astronomical target, HD 187123 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 187123 c is a rare exoplanet

HD 187123 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.