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Rare exoplanet 39 EP

WASP-139 b

RA 49.5622° · Dec -41.3020° · exoplanet

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Score breakdown

· 5 badges
39 pts · Rare
Rare 50 pts → Epic
  • Two suns in its sky +12
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 39

11 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Tidally locked · +10
  • Orbits a Sun-like star · +8
  • Two suns in its sky · +12

Trivia

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

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • 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 12.5 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 November — that's when to go looking.

Could we get there?

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

Properties

density gcc
0.31
diameter km
114387.3966
discovery facility
SuperWASP-South
discovery method
Transit
discovery year
2016
dist ly
692.9902
eccentricity
0
eq temp k
910
host star teff
5310
inclination
88.9
insolation
120.7076
mag
12.456
mass earth
37.1861
multi star system
yes
name
WASP-139 b
orbital period days
5.9243
radius earth
8.9672
semi major au
0.062
spect
K0
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About WASP-139 b

WASP-139 b is a rare exoplanet. It lies about 693 light-years from Earth, shines at apparent magnitude 12.46, has spectral type K0 and has an equilibrium temperature near 910 K.

It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.

How to see it

At apparent magnitude 12.46, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, WASP-139 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 WASP-139 b is a rare exoplanet

WASP-139 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 5 science badges — Confirmed exoplanet, Gas giant, Tidally locked, Orbits a Sun-like star and Two suns in its sky — 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.