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Epic exoplanet 61 EP

TOI-1789 b

RA 142.7434° · Dec 26.5400° · exoplanet

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Score breakdown

· 8 badges
61 pts · Epic
Epic 78 pts → Anomaly
  • Lava world +14
  • Puffy low-density world +12
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
  • Found by TESS +4
Total score 61

17 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • Puffy low-density world · +12
  • Blasted by starlight · +4
  • Found by TESS · +4
  • Orbits a Sun-like star · +8

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 9.7 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 February — that's when to go looking.

Properties

density gcc
0.28
diameter km
205896.9595
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2021
dist ly
747.1158
eq temp k
1927
host star teff
5991
inclination
78.41
insolation
2300
mag
9.721
mass earth
222.4799
name
TOI-1789 b
orbital period days
3.2087
radius earth
16.1409
semi major au
0.0488
spect
F
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About TOI-1789 b

TOI-1789 b is an epic exoplanet. It lies about 747.1 light-years from Earth, shines at apparent magnitude 9.72, has spectral type F and has an equilibrium temperature near 1,927 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 9.72, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-1789 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-1789 b is an epic exoplanet

TOI-1789 b scores 61 points on Spacedle's rarity scale, which places it in the epic tier. Another 17 points would lift it into a rarer tier.

That score comes from 8 science badges — Confirmed exoplanet, Gas giant, Lava world, Tidally locked, Puffy low-density world, Blasted by starlight, 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.