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Epic exoplanet 51 EP

HD 10647 b

RA 25.6234° · Dec -53.7413° · exoplanet

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Score breakdown

· 4 badges
51 pts · Epic
Epic 78 pts → Anomaly
  • In the habitable zone +30
  • Its star is visible to the naked eye +12
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 51

27 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Its star is visible to the naked eye · +12

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

What it actually is

  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.
  • What the zone means. The habitable zone is only about temperature: it is the band where liquid water could survive on a surface. It is a promising address, not evidence of anything living.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 5.5 you can see it with your own eyes from a dark site.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Properties

density gcc
0.625
diameter km
176035.56
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2006
dist ly
56.5414
eccentricity
0.15
eq temp k
221.54
habitable zone
yes
host star teff
6218
insolation
0.3471
mag
5.52
mass earth
298.75
name
HD 10647 b
orbital period days
989.2
radius earth
13.8
semi major au
2.015
spect
F9 V
sys num planets
1
sys num stars
1

About HD 10647 b

HD 10647 b is an epic exoplanet. It lies about 56.5 light-years from Earth, shines at apparent magnitude 5.52, has spectral type F9 V and has an equilibrium temperature near 222 K.

Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

How to see it

At apparent magnitude 5.52, it can be glimpsed with the unaided eye under dark skies.

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 an epic exoplanet

HD 10647 b scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 27 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Gas giant and Its star is visible to the naked eye — 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.