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Rare exoplanet 47 EP

TOI-172 b

RA 316.6319° · Dec -26.6929° · exoplanet

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Score breakdown

· 7 badges
47 pts · Rare
Rare 50 pts → Epic
  • Hot Jupiter +10
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Gas giant +4
  • Found by TESS +4
Total score 47

3 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Gas giant · +4
  • Hot Jupiter · +10
  • Tidally locked · +10
  • Found by TESS · +4
  • Orbits a Sun-like star · +8

Trivia

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. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.

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 11.3 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 August — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 19.6 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
7.53
diameter km
137979.7972
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2019
dist ly
1118.1639
eccentricity
0.3806
eq temp k
1198
host star teff
5645
inclination
88.2
insolation
299
mag
11.299
mass earth
1722.6386
name
TOI-172 b
orbital period days
9.4772
radius earth
10.8167
semi major au
0.0914
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About TOI-172 b

TOI-172 b is a rare exoplanet. It lies about 1,118.2 light-years from Earth, shines at apparent magnitude 11.3, has an equilibrium temperature near 1,198 K and spans roughly 10.82 Earth radii.

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 11.3, a small backyard telescope will bring it into view.

Like any astronomical target, TOI-172 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-172 b is a rare exoplanet

TOI-172 b scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Gas giant, Hot Jupiter, Tidally locked, 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.