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Uncommon exoplanet 29 EP

GJ 9827 b

RA 351.7718° · Dec -1.2853° · exoplanet

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Score breakdown

· 4 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Tidally locked +10
  • Super-Earth +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
Total score 29

5 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Super-Earth · +8
  • Tidally locked · +10
  • Multi-planet system · +6

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.
  • Crowded system. One of at least 3 planets orbiting its star.

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 10.4 you'll want a small backyard telescope.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

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

Properties

density gcc
7.858
diameter km
18368.928
discovery facility
K2
discovery method
Transit
discovery year
2017
dist ly
96.7411
eccentricity
0
eq temp k
1035.01
host star teff
4236
inclination
87.6
insolation
318
mag
10.37
mass earth
4.28
name
GJ 9827 b
orbital period days
1.209
radius earth
1.44
semi major au
0.0189
spect
K7 V
sys num planets
3
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About GJ 9827 b

GJ 9827 b is an uncommon exoplanet. It lies about 96.7 light-years from Earth, shines at apparent magnitude 10.37, has spectral type K7 V and has an equilibrium temperature near 1,035 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 10.37, a small backyard telescope will bring it into view.

Like any astronomical target, GJ 9827 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 GJ 9827 b is an uncommon exoplanet

GJ 9827 b scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, Tidally locked 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.