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Common exoplanet 17 EP

HD 42012 b

RA 92.4855° · Dec 34.1342° · exoplanet

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Score breakdown

· 3 badges
17 pts · Common
Common 22 pts → Uncommon
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 17

5 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Orbits a Sun-like star · +8

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.

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 8.4 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • 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 December — 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. ≈ 2.1 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 187.4 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

density gcc
1.14
diameter km
172208.7
discovery facility
Haute-Provence Observatory
discovery method
Radial Velocity
discovery year
2017
dist ly
120.0202
eccentricity
0.2
eq temp k
182.63
host star teff
5405
insolation
0.1927
mag
8.44
mass earth
508.528
name
HD 42012 b
orbital period days
857.5
radius earth
13.5
semi major au
1.67
spect
K0
sys num planets
1
sys num stars
1

About HD 42012 b

HD 42012 b is a common exoplanet. It lies about 120 light-years from Earth, shines at apparent magnitude 8.44, has spectral type K0 and has an equilibrium temperature near 183 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 8.44, it is an easy target for binoculars.

Like any astronomical target, HD 42012 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 42012 b is a common exoplanet

HD 42012 b scores 17 points on Spacedle's rarity scale, which places it in the common tier. Another 5 points would lift it into a rarer tier.

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