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Rare exoplanet 37 EP

HD 102843 b

RA 177.5855° · Dec -1.2523° · exoplanet

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Score breakdown

· 5 badges
37 pts · Rare
Rare 50 pts → Epic
  • Puffy low-density world +12
  • Frozen world +8
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 37

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Frozen world · +8
  • Puffy low-density world · +12
  • Orbits a Sun-like star · +8

Trivia

What makes it special

  • Frozen world. A deep-frozen world, too far from its star's warmth for anything to stay liquid.

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.

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 9.3 you'll want a small backyard telescope.
  • 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 March — that's when to go looking.

Could we get there?

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

Properties

density gcc
0.278
diameter km
167106.22
discovery facility
Las Campanas Observatory
discovery method
Radial Velocity
discovery year
2019
dist ly
204.689
eccentricity
0.11
eq temp k
127.34
host star teff
5436
insolation
0.0438
mag
9.26
mass earth
113.9
name
HD 102843 b
orbital period days
3090.942
radius earth
13.1
semi major au
4.074
spect
K0 V
sys num planets
1
sys num stars
1

About HD 102843 b

HD 102843 b is a rare exoplanet. It lies about 204.7 light-years from Earth, shines at apparent magnitude 9.26, has spectral type K0 V and has an equilibrium temperature near 127 K.

A deep-frozen world, too far from its star's warmth for anything to stay liquid.

How to see it

At apparent magnitude 9.26, a small backyard telescope will bring it into view.

Like any astronomical target, HD 102843 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 102843 b is a rare exoplanet

HD 102843 b scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Frozen world, Puffy low-density world and Orbits a Sun-like star — 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.