← Back to dex
Uncommon exoplanet 23 EP

TOI-1728 b

RA 120.6117° · Dec 64.7972° · exoplanet

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

Computing the sky for your location…

Score breakdown

· 4 badges
23 pts · Uncommon
Uncommon 34 pts → Rare
  • Tidally locked +10
  • Confirmed exoplanet +5
  • Neptune-like +4
  • Found by TESS +4
Total score 23

11 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Neptune-like · +4
  • Tidally locked · +10
  • Found by TESS · +4

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. 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 12.4 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • Best time of year. It stands highest in the middle of the night around January — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 3.5 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.14
diameter km
64418.81
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2020
dist ly
198.2963
eccentricity
0.057
eq temp k
767
host star teff
3980
inclination
88.31
insolation
57.78
mag
12.39
mass earth
26.78
name
TOI-1728 b
orbital period days
3.4915
radius earth
5.05
semi major au
0.0391
spect
M0
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About TOI-1728 b

TOI-1728 b is an uncommon exoplanet. It lies about 198.3 light-years from Earth, shines at apparent magnitude 12.39, has spectral type M0 and has an equilibrium temperature near 767 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 12.39, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, TOI-1728 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-1728 b is an uncommon exoplanet

TOI-1728 b scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Neptune-like, Tidally locked 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.