Epic exoplanet 67 EP

HD 154391 b

RA 255.3201° · Dec 60.6489° · exoplanet

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Score breakdown

· 5 badges

67 pts · Epic

Epic 68 pts → Anomaly

In the habitable zone +30
Denser than iron +18
Long-period world +10
Confirmed exoplanet +5
Gas giant +4

Total score 67

1 more point to reach Anomaly.

Badges

Confirmed exoplanet · +5
In the habitable zone · +30
Gas giant · +4
Long-period world · +10
Denser than iron · +18

Trivia

What makes it special

Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist.
Heavyweight. Packed denser than solid iron.

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 5.8 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 514.1 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 3292 years in a starship at a tenth of light speed.
Distance. 329 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1697.

Saying hello

Say hello. A radio message and its reply would take 658 years round-trip.

Standing on it

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

By the numbers

Size. About 12.5× the width of Earth.
Volume. About 1953 Earths could fit inside it.
Mass. Roughly 2892× Earth's mass — about 9.1 Jupiters.
Your weight. You'd weigh about 18.5× your Earth weight standing here.
Density. Denser than solid iron.
Temperature. A surprisingly temperate -20°C average.

How we found it

Discovery. Found by Multiple Observatories using the radial velocity method.

Properties

density gcc: 8.14
discovery facility: Multiple Observatories
discovery method: Radial Velocity
dist ly: 329.2447
eccentricity: 0.2
eq temp k: 253.57
habitable zone: yes
insolation: 0.685
mass earth: 2892.2385
name: HD 154391 b
orbital period days: 5163
radius earth: 12.5
sys num planets: 1

About HD 154391 b

HD 154391 b is an epic exoplanet. It lies about 329.2 light-years from Earth, has an equilibrium temperature near 254 K, spans roughly 12.5 Earth radii and weighs about 2,892.24 Earth masses.

Sits where it's neither too hot nor too cold — liquid water could exist.

How to see it

Like any astronomical target, HD 154391 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 154391 b is an epic exoplanet

HD 154391 b scores 67 points on Spacedle's rarity scale, which places it in the epic tier. Another 1 point would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, In the habitable zone, Gas giant, Long-period world and Denser than iron — 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.