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Rare exoplanet 37 EP

tau Gem b

RA 107.7847° · Dec 30.2450° · exoplanet

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Score breakdown

· 4 badges
37 pts · Rare
Rare 46 pts → Epic
  • Denser than iron +18
  • Hot Jupiter +10
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 37

9 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Denser than iron · +18

Trivia

What makes it special

  • 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. ≈ 6.5 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 573.1 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 3670 years in a starship at a tenth of light speed.
  • Distance. 367 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1659.

Saying hello

  • Say hello. A radio message and its reply would take 734 years round-trip.

Standing on it

  • A year here. A full year lasts just 306 Earth days.

By the numbers

  • Size. About 12.1× the width of Earth.
  • Volume. About 1772 Earths could fit inside it.
  • Mass. Roughly 6547× Earth's mass — about 20.6 Jupiters.
  • Your weight. You'd weigh about 44.7× your Earth weight standing here.
  • Density. Denser than solid iron.
  • Temperature. Around 740°C — hotter than a self-cleaning oven.

How we found it

  • Discovery. Found by Lick Observatory using the radial velocity method.

Properties

density gcc
20.3
discovery facility
Lick Observatory
discovery method
Radial Velocity
dist ly
367.0462
eccentricity
0.031
eq temp k
1012.69
insolation
241.3109
mass earth
6547
name
tau Gem b
orbital period days
305.5
radius earth
12.1
sys num planets
1

About tau Gem b

tau Gem b is a rare exoplanet. It lies about 367 light-years from Earth, has an equilibrium temperature near 1,013 K, spans roughly 12.1 Earth radii and weighs about 6,547 Earth masses.

Packed denser than solid iron.

How to see it

Like any astronomical target, tau Gem 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 tau Gem b is a rare exoplanet

tau Gem b scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter 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.

spacedle A daily roll through the real universe. © 2026 spacedle. Buy me a coffee

Sky imagery and survey data courtesy of Aladin Lite & CDS, Strasbourg. Object data from the NASA Exoplanet Archive, JPL Small-Body Database, and the ATNF Pulsar Catalogue.