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Epic exoplanet 59 EP

WASP-151 b

RA 349.0635° · Dec 0.3067° · exoplanet

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Score breakdown

· 7 badges
59 pts · Epic
Epic 78 pts → Anomaly
  • Lava world +14
  • Puffy low-density world +12
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 59

19 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • Puffy low-density world · +12
  • Orbits a Sun-like star · +8

Trivia

What makes it special

  • Lava world. Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

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 12.8 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 September — that's when to go looking.

Properties

density gcc
0.2507
diameter km
169722.0075
discovery facility
SuperWASP-South
discovery method
Transit
discovery year
2017
dist ly
1477.8096
eccentricity
0
eq temp k
1312
host star teff
5871
inclination
88.25
insolation
460
mag
12.821
mass earth
100.4338
name
WASP-151 b
orbital period days
4.5335
radius earth
13.3051
semi major au
0.055
spect
G1
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About WASP-151 b

WASP-151 b is an epic exoplanet. It lies about 1,477.8 light-years from Earth, shines at apparent magnitude 12.82, has spectral type G1 and has an equilibrium temperature near 1,312 K.

Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

How to see it

At apparent magnitude 12.82, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, WASP-151 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-151 b is an epic exoplanet

WASP-151 b scores 59 points on Spacedle's rarity scale, which places it in the epic tier. Another 19 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Gas giant, Lava world, Tidally locked, 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.