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Common exoplanet 15 EP

HD 159243 c

RA 263.3395° · Dec 5.7008° · exoplanet

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Score breakdown

· 3 badges
15 pts · Common
Common 22 pts → Uncommon
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 15

7 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Multi-planet system · +6

Trivia

What it actually is

  • 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.
  • Crowded system. One of at least 2 planets orbiting its star.

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 8.7 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • 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 June — 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. ≈ 4.2 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.38
diameter km
170933.08
discovery facility
Haute-Provence Observatory
discovery method
Radial Velocity
discovery year
2013
dist ly
239.0903
eccentricity
0.075
eq temp k
349.35
host star teff
6123
insolation
2.0315
mag
8.65
mass earth
603.9
name
HD 159243 c
orbital period days
248.4
radius earth
13.4
semi major au
0.8
spect
G0 V
sys num planets
2
sys num stars
1

Nearby objects

About HD 159243 c

HD 159243 c is a common exoplanet. It lies about 239.1 light-years from Earth, shines at apparent magnitude 8.65, has spectral type G0 V and has an equilibrium temperature near 349 K.

Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

How to see it

At apparent magnitude 8.65, it is an easy target for binoculars.

Like any astronomical target, HD 159243 c 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 159243 c is a common exoplanet

HD 159243 c scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Gas giant 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.