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Rare exoplanet 39 EP

HD 10442 b

RA 25.4715° · Dec 2.7044° · exoplanet

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Score breakdown

· 3 badges
39 pts · Rare
Rare 50 pts → Epic
  • In the habitable zone +30
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 39

11 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 on a surface here.

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. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 7.8 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Could we get there?

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

Properties

density gcc
1.03
diameter km
173484.32
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2014
dist ly
441.5304
eccentricity
0.132
eq temp k
234.49
habitable zone
yes
host star teff
4912
insolation
0.5054
mag
7.828
mass earth
472.6132
name
HD 10442 b
orbital period days
1032.3
radius earth
13.6
semi major au
2.01
spect
K0 IV
sys num planets
1
sys num stars
1

About HD 10442 b

HD 10442 b is a rare exoplanet. It lies about 441.5 light-years from Earth, shines at apparent magnitude 7.83, has spectral type K0 IV and has an equilibrium temperature near 234 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 7.83, it is an easy target for binoculars.

Like any astronomical target, HD 10442 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 10442 b is a rare exoplanet

HD 10442 b scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 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.