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Uncommon exoplanet 29 EP

WASP-91 b

RA 357.8464° · Dec -70.1529° · exoplanet

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Score breakdown

· 4 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Hot Jupiter +10
  • Tidally locked +10
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 29

5 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Tidally locked · +10

Trivia

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 you'll want a small backyard telescope.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 8.6 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.59
diameter km
147273.7732
discovery facility
SuperWASP-South
discovery method
Transit
discovery year
2017
dist ly
489.0448
eccentricity
0
eq temp k
1160
host star teff
4920
inclination
86.8
insolation
332.5562
mag
11.98
mass earth
425.8922
name
WASP-91 b
orbital period days
2.7986
radius earth
11.5453
semi major au
0.037
spect
K3
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About WASP-91 b

WASP-91 b is an uncommon exoplanet. It lies about 489 light-years from Earth, shines at apparent magnitude 11.98, has spectral type K3 and has an equilibrium temperature near 1,160 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 11.98, a small backyard telescope will bring it into view.

Like any astronomical target, WASP-91 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-91 b is an uncommon exoplanet

WASP-91 b scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter and Tidally locked — 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.