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Epic exoplanet 65 EP

WASP-18 b

RA 24.3545° · Dec -45.6778° · exoplanet

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Score breakdown

· 6 badges
65 pts · Epic
Epic 78 pts → Anomaly
  • Ultra-hot Jupiter +26
  • Ultra-short period +14
  • Two suns in its sky +12
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
Total score 65

13 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Ultra-hot Jupiter · +26
  • Ultra-short period · +14
  • Blasted by starlight · +4
  • Two suns in its sky · +12

Trivia

What makes it special

  • Ultra-hot Jupiter. So hot that iron vaporises on the dayside, blows around to the night side and rains back down as molten metal.

Hard to believe

  • A year in a day. Its entire year is over in 22.6 hours. Birthdays here would come round faster than meals.

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. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.

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.
  • 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
6.6
diameter km
177300.1595
discovery facility
SuperWASP
discovery method
Transit
discovery year
2009
dist ly
402.7472
eccentricity
0.0051
eq temp k
2429
host star teff
6432
inclination
83.5
insolation
5805
mag
9.28
mass earth
3241.8498
multi star system
yes
name
WASP-18 b
orbital period days
0.9415
radius earth
13.8991
semi major au
0.0202
spect
F6 IV-V
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About WASP-18 b

WASP-18 b is an epic exoplanet. It lies about 402.7 light-years from Earth, shines at apparent magnitude 9.28, has spectral type F6 IV-V and has an equilibrium temperature near 2,429 K.

So hot that iron vaporises on the dayside, blows around to the night side and rains back down as molten metal.

How to see it

At apparent magnitude 9.28, a small backyard telescope will bring it into view.

Like any astronomical target, WASP-18 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-18 b is an epic exoplanet

WASP-18 b scores 65 points on Spacedle's rarity scale, which places it in the epic tier. Another 13 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Ultra-hot Jupiter, Ultra-short period, Blasted by starlight 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.