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Rare exoplanet 39 EP

TOI-5398 b

RA 161.8796° · Dec 36.3294° · exoplanet

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Score breakdown

· 6 badges
39 pts · Rare
Rare 50 pts → Epic
  • Puffy low-density world +12
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
  • Found by TESS +4
Total score 39

11 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Puffy low-density world · +12
  • Multi-planet system · +6
  • Found by TESS · +4
  • Orbits a Sun-like star · +8

Trivia

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.
  • Crowded system. One of at least 2 planets orbiting its star.

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 10.1 you'll want a small backyard telescope.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Properties

density gcc
0.29
diameter km
131388.86
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2022
dist ly
426.7914
eccentricity
0.13
eq temp k
947
host star teff
6000
inclination
89.21
insolation
118.413
mag
10.059
mass earth
58.7
name
TOI-5398 b
orbital period days
10.5905
radius earth
10.3
semi major au
0.098
spect
G V
sys num planets
2
sys num stars
1

About TOI-5398 b

TOI-5398 b is a rare exoplanet. It lies about 426.8 light-years from Earth, shines at apparent magnitude 10.06, has spectral type G V and has an equilibrium temperature near 947 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 10.06, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-5398 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 TOI-5398 b is a rare exoplanet

TOI-5398 b scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Puffy low-density world, Multi-planet system, Found by TESS 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.