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Rare exoplanet 37 EP

WASP-99 b

RA 39.8977° · Dec -50.0082° · exoplanet

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Score breakdown

· 5 badges
37 pts · Rare
Rare 50 pts → Epic
  • Lava world +14
  • Tidally locked +10
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
Total score 37

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • Blasted by starlight · +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.

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. Too light to be solid rock and too heavy to be all gas: most likely a deep global ocean or a thick steamy envelope over a rocky core.

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 9.5 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.

Could we get there?

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

Properties

density gcc
2.79
diameter km
145843.9307
discovery facility
SuperWASP
discovery method
Transit
discovery year
2014
dist ly
517.4791
eccentricity
0
eq temp k
1480
host star teff
6150
inclination
88.8
insolation
2005.426
mag
9.475
mass earth
772.3269
name
WASP-99 b
orbital period days
5.7525
radius earth
11.4332
semi major au
0.0717
spect
F8
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About WASP-99 b

WASP-99 b is a rare exoplanet. It lies about 517.5 light-years from Earth, shines at apparent magnitude 9.47, has spectral type F8 and has an equilibrium temperature near 1,480 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 9.47, a small backyard telescope will bring it into view.

Like any astronomical target, WASP-99 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-99 b is a rare exoplanet

WASP-99 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, Lava world, Tidally locked and Blasted by starlight — 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.