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Uncommon exoplanet 28 EP

TOI-178 g

RA 7.3020° · Dec -30.4541° · exoplanet

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Score breakdown

· 4 badges
28 pts · Uncommon
Uncommon 34 pts → Rare
  • Richly packed system +14
  • Confirmed exoplanet +5
  • Sub-Neptune +5
  • Found by TESS +4
Total score 28

6 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Sub-Neptune · +5
  • Richly packed system · +14
  • Found by TESS · +4

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 6 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 12 you'll want a small backyard telescope.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Properties

density gcc
0.9594
diameter km
37490.4718
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2021
dist ly
204.4966
eccentricity
0.0004
eq temp k
470
host star teff
4316
inclination
88.823
insolation
19.4978
mag
11.955
mass earth
4.4
name
TOI-178 g
orbital period days
20.7166
radius earth
2.939
semi major au
0.1275
spect
K
sys num planets
6
sys num stars
1

About TOI-178 g

TOI-178 g is an uncommon exoplanet. It lies about 204.5 light-years from Earth, shines at apparent magnitude 11.96, has spectral type K and has an equilibrium temperature near 470 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 11.96, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-178 g 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-178 g is an uncommon exoplanet

TOI-178 g scores 28 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Sub-Neptune, Richly packed system and Found by TESS — 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.