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Rare exoplanet 43 EP

TOI-3984 A b

RA 226.3371° · Dec 36.7870° · exoplanet

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Score breakdown

· 6 badges
43 pts · Rare
Rare 50 pts → Epic
  • Two suns in its sky +12
  • Tidally locked +10
  • Orbits a red dwarf +8
  • Confirmed exoplanet +5
  • Gas giant +4
  • Found by TESS +4
Total score 43

7 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Tidally locked · +10
  • Found by TESS · +4
  • Orbits a red dwarf · +8
  • Two suns in its sky · +12

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.

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 15.7 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 May — that's when to go looking.

Could we get there?

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

Properties

density gcc
0.49
diameter km
100773.98
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2023
dist ly
355.1284
eccentricity
0.23
eq temp k
563
host star teff
3476
inclination
89.5
insolation
16.7
mag
15.694
mass earth
44
multi star system
yes
name
TOI-3984 A b
orbital period days
4.3533
radius earth
7.9
semi major au
0.041
spect
M4+/-0.5
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About TOI-3984 A b

TOI-3984 A b is a rare exoplanet. It lies about 355.1 light-years from Earth, shines at apparent magnitude 15.69, has spectral type M4+/-0.5 and has an equilibrium temperature near 563 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 15.69, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, TOI-3984 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-3984 A b is a rare exoplanet

TOI-3984 A b scores 43 points on Spacedle's rarity scale, which places it in the rare tier. Another 7 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Tidally locked, Found by TESS, Orbits a red dwarf 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.