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Rare exoplanet 39 EP

HD 87646 b

RA 151.6695° · Dec 17.8950° · exoplanet

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Score breakdown

· 5 badges
39 pts · Rare
Rare 50 pts → Epic
  • Two suns in its sky +12
  • Hot Jupiter +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 39

11 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Orbits a Sun-like star · +8
  • Two suns in its sky · +12

Trivia

Hard to believe

  • Denser than iron. It is packed tighter than solid iron — whatever it is made of, it is not ordinary rock.

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.

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 8.1 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 February — that's when to go looking.

Could we get there?

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

Properties

density gcc
11.4
diameter km
158176.88
discovery facility
Apache Point Observatory
discovery method
Radial Velocity
discovery year
2016
dist ly
239.9971
eccentricity
0.05
eq temp k
1012.7
host star teff
5770
insolation
665.812
mag
8.07
mass earth
3941.092
multi star system
yes
name
HD 87646 b
orbital period days
13.481
radius earth
12.4
semi major au
0.117
spect
G
sys num planets
1
sys num stars
3

About HD 87646 b

HD 87646 b is a rare exoplanet. It lies about 240 light-years from Earth, shines at apparent magnitude 8.07, has spectral type G and has an equilibrium temperature near 1,013 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 8.07, it is an easy target for binoculars.

Like any astronomical target, HD 87646 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 87646 b is a rare exoplanet

HD 87646 b scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Orbits a Sun-like star and Two suns in its sky — 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.