Epic exoplanet 51 EP

HD 153557 d

RA 254.4707° · Dec 47.3679° · exoplanet

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Score breakdown

· 6 badges

51 pts · Epic

Epic 68 pts → Anomaly

Denser than iron +18
Long-period world +10
Frozen world +8
Multi-planet system +6
Confirmed exoplanet +5
Gas giant +4

Total score 51

17 more points to reach Anomaly.

Badges

Confirmed exoplanet · +5
Gas giant · +4
Frozen world · +8
Long-period world · +10
Denser than iron · +18
Multi-planet system · +6

Trivia

What makes it special

Frozen world. A deep-frozen world far from its star's warmth.
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. ≈ 1 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 91.4 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 585 years in a starship at a tenth of light speed.
Distance. 58.5 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1967.

Saying hello

Say hello. A radio message and its reply would take 117 years round-trip.

Standing on it

A year here. A full year lasts about 111 Earth years.

By the numbers

Size. About 11.9× the width of Earth.
Volume. About 1685 Earths could fit inside it.
Mass. Roughly 8726× Earth's mass — about 27.5 Jupiters.
Your weight. You'd weigh about 61.6× your Earth weight standing here.
Density. Denser than solid iron.
Temperature. A frigid -230°C — colder than dry ice.

How we found it

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

Cosmic context

Crowded system. One of at least 3 planets orbiting its star.

Properties

density gcc: 28.5
discovery facility: Multiple Observatories
discovery method: Radial Velocity
dist ly: 58.5163
eccentricity: 0.152
eq temp k: 43.47
insolation: 0.0006
mass earth: 8725.6611
name: HD 153557 d
orbital period days: 40654.6481
radius earth: 11.9
sys num planets: 3

About HD 153557 d

HD 153557 d is an epic exoplanet. It lies about 58.5 light-years from Earth, has an equilibrium temperature near 43 K, spans roughly 11.9 Earth radii and weighs about 8,725.66 Earth masses.

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

How to see it

Like any astronomical target, HD 153557 d 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 153557 d is an epic exoplanet

HD 153557 d scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 17 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Frozen world, Long-period world, Denser than iron 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.