← Back to dex
Rare exoplanet 39 EP

HD 10647 b

RA 25.6234° · Dec -53.7413° · exoplanet

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

Computing the sky for your location…

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. ≈ 993.6 thousand years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 88.3 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 565 years in a starship at a tenth of light speed.
  • Distance. 56.5 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1969.

Saying hello

  • Say hello. A radio message and its reply would take 113 years round-trip.

Standing on it

  • A year here. A full year lasts about 2.7 Earth years.

By the numbers

  • Size. About 13.8× the width of Earth.
  • Volume. About 2628 Earths could fit inside it.
  • Mass. Roughly 299× Earth's mass — about 0.9 Jupiters.
  • Your weight. You'd weigh about 1.6× your Earth weight standing here.
  • Density. Less dense than water — drop it in a big enough ocean and it would float.
  • Temperature. A frigid -52°C — colder than dry ice.

How we found it

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

Properties

density gcc
0.625
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
dist ly
56.5414
eccentricity
0.15
eq temp k
221.54
habitable zone
yes
insolation
0.3471
mass earth
298.75
name
HD 10647 b
orbital period days
989.2
radius earth
13.8
sys num planets
1

About HD 10647 b

HD 10647 b is a rare exoplanet. It lies about 56.5 light-years from Earth, has an equilibrium temperature near 222 K, spans roughly 13.8 Earth radii and weighs about 298.75 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 10647 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 10647 b is a rare exoplanet

HD 10647 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.

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.