Common exoplanet 15 EP

HD 128311 b

RA 219.0032° · Dec 9.7454° · exoplanet

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Score breakdown

· 3 badges

15 pts · Common

Common 24 pts → Uncommon

Multi-planet system +6
Confirmed exoplanet +5
Gas giant +4

Total score 15

9 more points to reach Uncommon.

Badges

Confirmed exoplanet · +5
Gas giant · +4
Multi-planet system · +6

Trivia

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 935.9 thousand years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 83.2 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 533 years in a starship at a tenth of light speed.
Distance. 53.3 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1973.

Saying hello

Say hello. A radio message and its reply would take 107 years round-trip.

Standing on it

A year here. A full year lasts just 453 Earth days.

By the numbers

Size. About 13.5× the width of Earth.
Volume. About 2460 Earths could fit inside it.
Mass. Roughly 562× Earth's mass — about 1.8 Jupiters.
Your weight. You'd weigh about 3.1× your Earth weight standing here.
Temperature. A frigid -73°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: 1.26
discovery facility: W. M. Keck Observatory
discovery method: Radial Velocity
dist ly: 53.2587
eccentricity: 0.303
eq temp k: 200.47
insolation: 0.262
mass earth: 562.2413
name: HD 128311 b
orbital period days: 453.019
radius earth: 13.5
sys num planets: 2

About HD 128311 b

HD 128311 b is a common exoplanet. It lies about 53.3 light-years from Earth, has an equilibrium temperature near 200 K, spans roughly 13.5 Earth radii and weighs about 562.24 Earth masses.

One of at least 2 planets orbiting its star.

How to see it

Like any astronomical target, HD 128311 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 128311 b is a common exoplanet

HD 128311 b scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 9 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Gas giant 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.