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Uncommon exoplanet 30 EP

HD 86728 b

RA 150.2501° · Dec 31.9218° · exoplanet

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Score breakdown

· 4 badges
30 pts · Uncommon
Uncommon 34 pts → Rare
  • Its star is visible to the naked eye +12
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Sub-Neptune +5
Total score 30

4 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Sub-Neptune · +5
  • Its star is visible to the naked eye · +12
  • 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. Too light to be solid rock and too heavy to be all gas: most likely a deep global ocean or a thick steamy envelope over a rocky core.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 5.4 you can see it with your own eyes from a dark site.
  • 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 February — 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. ≈ 855.1 thousand years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.86
diameter km
38651.286
discovery facility
Multiple Observatories
discovery method
Radial Velocity
discovery year
2025
dist ly
48.6631
eccentricity
0.067
eq temp k
687.36
host star teff
5610
insolation
37.1828
mag
5.3799
mass earth
9.43
name
HD 86728 b
orbital period days
31.1515
radius earth
3.03
semi major au
0.1916
spect
G1V
sys num planets
1
sys num stars
1

About HD 86728 b

HD 86728 b is an uncommon exoplanet. It lies about 48.7 light-years from Earth, shines at apparent magnitude 5.38, has spectral type G1V and has an equilibrium temperature near 687 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 5.38, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HD 86728 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 HD 86728 b is an uncommon exoplanet

HD 86728 b scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Sub-Neptune, Its star is visible to the naked eye 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.