← Back to dex
Rare exoplanet 45 EP

TOI-199 c

RA 80.1059° · Dec -59.8954° · exoplanet

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 4 badges
45 pts · Rare
Rare 50 pts → Epic
  • In the habitable zone +30
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 45

5 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Multi-planet system · +6

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

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

  • 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.
  • What the zone means. The habitable zone is only about temperature: it is the band where liquid water could survive on a surface. It is a promising address, not evidence of anything living.
  • 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 10.7 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.

Properties

density gcc
0.33
diameter km
145420.68
discovery facility
Multiple Observatories
discovery method
Transit Timing Variations
discovery year
2023
dist ly
333.5597
eccentricity
0.096
eq temp k
255.43
habitable zone
yes
host star teff
5255
inclination
90
insolation
0.7048
mag
10.701
mass earth
88.992
name
TOI-199 c
orbital period days
273.69
radius earth
11.4
semi major au
0.807
spect
G9 V
sys num planets
2
sys num stars
1

About TOI-199 c

TOI-199 c is a rare exoplanet. It lies about 333.6 light-years from Earth, shines at apparent magnitude 10.7, has spectral type G9 V and has an equilibrium temperature near 255 K.

Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

How to see it

At apparent magnitude 10.7, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-199 c 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-199 c is a rare exoplanet

TOI-199 c scores 45 points on Spacedle's rarity scale, which places it in the rare tier. Another 5 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Gas giant and Multi-planet system — 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.