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Common exoplanet 18 EP

HD 1666 b

RA 5.2180° · Dec -19.9315° · exoplanet

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Score breakdown

· 3 badges
18 pts · Common
Common 24 pts → Uncommon
  • Eccentric orbit +9
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 18

6 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Eccentric orbit · +9

Trivia

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 6.8 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 600.5 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 3846 years in a starship at a tenth of light speed.
  • Distance. 385 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1641.

Saying hello

  • Say hello. A radio message and its reply would take 769 years round-trip.

Standing on it

  • A year here. A full year lasts just 270 Earth days.

By the numbers

  • Size. About 12.7× the width of Earth.
  • Volume. About 2048 Earths could fit inside it.
  • Mass. Roughly 2040× Earth's mass — about 6.4 Jupiters.
  • Your weight. You'd weigh about 12.6× your Earth weight standing here.
  • Temperature. A scorching 163°C on average.

How we found it

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

Properties

density gcc
5.47
discovery facility
Multiple Observatories
discovery method
Radial Velocity
dist ly
384.564
eccentricity
0.63
eq temp k
436.47
insolation
6.0778
mass earth
2040
name
HD 1666 b
orbital period days
270
radius earth
12.7
sys num planets
1

About HD 1666 b

HD 1666 b is a common exoplanet. It lies about 384.6 light-years from Earth, has an equilibrium temperature near 436 K, spans roughly 12.7 Earth radii and weighs about 2,040 Earth masses.

About 12.7× the width of Earth.

How to see it

Like any astronomical target, HD 1666 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 1666 b is a common exoplanet

HD 1666 b scores 18 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

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