Rare exoplanet 39 EP

HD 188015 b

RA 298.0192° · Dec 28.1000° · exoplanet

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Score breakdown

· 3 badges

39 pts · Rare

Rare 46 pts → Epic

In the habitable zone +30
Confirmed exoplanet +5
Gas giant +4

Total score 39

7 more points to reach Epic.

Badges

Confirmed exoplanet · +5
In the habitable zone · +30
Gas giant · +4

Trivia

What makes it special

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

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 2.9 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 258 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 1653 years in a starship at a tenth of light speed.
Distance. 165 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1861.

Saying hello

Say hello. A radio message and its reply would take 331 years round-trip.

Standing on it

A year here. A full year lasts just 461 Earth days.

By the numbers

Size. About 13.6× the width of Earth.
Volume. About 2515 Earths could fit inside it.
Mass. Roughly 477× Earth's mass — about 1.5 Jupiters.
Your weight. You'd weigh about 2.6× your Earth weight standing here.
Temperature. A surprisingly temperate -5°C average.

How we found it

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

Properties

density gcc: 1.04
discovery facility: W. M. Keck Observatory
discovery method: Radial Velocity
dist ly: 165.2652
eccentricity: 0.137
eq temp k: 267.98
habitable zone: yes
insolation: 0.7914
mass earth: 476.72
name: HD 188015 b
orbital period days: 461.2
radius earth: 13.6
sys num planets: 1

About HD 188015 b

HD 188015 b is a rare exoplanet. It lies about 165.3 light-years from Earth, has an equilibrium temperature near 268 K, spans roughly 13.6 Earth radii and weighs about 476.72 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 188015 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 188015 b is a rare exoplanet

HD 188015 b scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 7 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, In the habitable zone and Gas giant — 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.