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Epic exoplanet 69 EP

TOI-3540 A b

RA 328.9114° · Dec 28.1795° · exoplanet

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Score breakdown

· 8 badges
69 pts · Epic
Epic 78 pts → Anomaly
  • Lava world +14
  • Puffy low-density world +12
  • Two suns in its sky +12
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
  • Found by TESS +4
Total score 69

9 more points to reach Anomaly.

Badges

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

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.

Find it in the sky

  • How to spot it. At magnitude 11.5 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 August — that's when to go looking.

Standing on it

  • A year here. A full year lasts just 3.1 Earth days.

Properties

density gcc
0.065
diameter km
300266.3992
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2022
eccentricity
0
eq temp k
1498
host star teff
5810
inclination
81.93
insolation
841.3
mag
11.514
mass earth
375.0375
multi star system
yes
name
TOI-3540 A b
orbital period days
3.12
radius earth
23.5389
semi major au
0.0429
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About TOI-3540 A b

TOI-3540 A b is an epic exoplanet. It shines at apparent magnitude 11.51, has an equilibrium temperature near 1,498 K, spans roughly 23.54 Earth radii and weighs about 375.04 Earth masses.

Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

How to see it

At apparent magnitude 11.51, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-3540 A 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-3540 A b is an epic exoplanet

TOI-3540 A b scores 69 points on Spacedle's rarity scale, which places it in the epic tier. Another 9 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, Found by TESS, Orbits a Sun-like star and Two suns in its sky — 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.