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Uncommon exoplanet 29 EP

K2-315 b

RA 228.0211° · Dec -20.1082° · exoplanet

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Score breakdown

· 3 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Earth-sized +16
  • Orbits a red dwarf +8
  • Confirmed exoplanet +5
Total score 29

5 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Earth-sized · +16
  • Orbits a red dwarf · +8

Trivia

What makes it special

  • Earth-sized. Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.

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. Its density says rock, though lighter than Earth's mix: probably less iron, or a thick shell of water and ice over the top.

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 17.7 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 May — that's when to go looking.

Could we get there?

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

Properties

density gcc
5.18
diameter km
12118.39
discovery facility
K2
discovery method
Transit
discovery year
2020
dist ly
185.8065
eq temp k
460
host star teff
3300
inclination
88.74
insolation
7.45
mag
17.67
mass earth
0.809
name
K2-315 b
orbital period days
3.1443
radius earth
0.95
spect
M(3.5+/-0.5) V
sys num planets
1
sys num stars
1

About K2-315 b

K2-315 b is an uncommon exoplanet. It lies about 185.8 light-years from Earth, shines at apparent magnitude 17.67, has spectral type M(3.5+/-0.5) V and has an equilibrium temperature near 460 K.

Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.

How to see it

At apparent magnitude 17.67, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, K2-315 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 K2-315 b is an uncommon exoplanet

K2-315 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 3 science badges — Confirmed exoplanet, Earth-sized and Orbits a red dwarf — 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.