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Uncommon exoplanet 31 EP

WASP-108 b

RA 195.8282° · Dec -49.6398° · exoplanet

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Score breakdown

· 5 badges
31 pts · Uncommon
Uncommon 34 pts → Rare
  • Lava world +14
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
  • Found by TESS +4
Total score 31

3 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Blasted by starlight · +4
  • Found by TESS · +4

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 11.2 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 April — that's when to go looking.

Properties

density gcc
0.4774
diameter km
193028.3995
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2020
dist ly
844.0167
eccentricity
0
eq temp k
1589
host star teff
6783
inclination
89.2
insolation
1360.1641
mag
11.211
mass earth
283.5029
name
WASP-108 b
orbital period days
2.6756
radius earth
15.1321
spect
F9
sys num planets
1
sys num stars
1

About WASP-108 b

WASP-108 b is an uncommon exoplanet. It lies about 844 light-years from Earth, shines at apparent magnitude 11.21, has spectral type F9 and has an equilibrium temperature near 1,589 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 11.21, a small backyard telescope will bring it into view.

Like any astronomical target, WASP-108 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-108 b is an uncommon exoplanet

WASP-108 b scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 3 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Lava world, Blasted by starlight and Found by TESS — 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.