← Back to dex
Rare exoplanet 40 EP

51 Eri b

RA 69.4007° · Dec -2.4738° · exoplanet

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 4 badges
40 pts · Rare
Rare 46 pts → Epic
  • Directly imaged +16
  • Long-period world +10
  • Eccentric orbit +9
  • Confirmed exoplanet +5
Total score 40

6 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Long-period world · +10
  • Eccentric orbit · +9
  • Directly imaged · +16

Trivia

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 1.7 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 151.5 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 971 years in a starship at a tenth of light speed.
  • Distance. 97.1 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1929.

Saying hello

  • Say hello. A radio message and its reply would take 194 years round-trip.

Standing on it

  • A year here. A full year lasts about 24.9 Earth years.

By the numbers

  • Mass. Roughly 3464× Earth's mass — about 10.9 Jupiters.
  • Temperature. Around 534°C — hotter than a self-cleaning oven.

How we found it

  • Discovery. Found by Gemini Observatory using the imaging method.

Properties

discovery facility
Gemini Observatory
discovery method
Imaging
dist ly
97.0559
eccentricity
0.57
eq temp k
807
insolation
0.0529
mass earth
3464.3296
name
51 Eri b
orbital period days
9100
sys num planets
1

About 51 Eri b

51 Eri b is a rare exoplanet. It lies about 97.1 light-years from Earth, has an equilibrium temperature near 807 K, weighs about 3,464.33 Earth masses and completes an orbit every 9,100 days.

Roughly 3464× Earth's mass — about 10.9 Jupiters.

How to see it

Like any astronomical target, 51 Eri 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 51 Eri b is a rare exoplanet

51 Eri b scores 40 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Long-period world, Eccentric orbit and Directly imaged — 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.