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Rare exoplanet 48 EP

HD 125390 b

RA 214.5387° · Dec 38.9669° · exoplanet

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Score breakdown

· 4 badges
48 pts · Rare
Rare 50 pts → Epic
  • In the habitable zone +30
  • Eccentric orbit +9
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 48

2 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Eccentric orbit · +9

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

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

  • What it is made of. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.
  • What the zone means. The habitable zone is only about temperature: it is the band where liquid water could survive on a surface. It is a promising address, not evidence of anything living.

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 8.2 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 April — that's when to go looking.

Properties

density gcc
28.2
diameter km
151798.78
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2019
dist ly
501.1289
eccentricity
0.597
eq temp k
320.26
habitable zone
yes
host star teff
4882
inclination
84.685
insolation
1.0874
mag
8.21
mass earth
8646.204
name
HD 125390 b
orbital period days
1757.3915
radius earth
11.9
semi major au
3.496
spect
G7 III
sys num planets
1
sys num stars
1

About HD 125390 b

HD 125390 b is a rare exoplanet. It lies about 501.1 light-years from Earth, shines at apparent magnitude 8.21, has spectral type G7 III and has an equilibrium temperature near 320 K.

Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

How to see it

At apparent magnitude 8.21, it is an easy target for binoculars.

Like any astronomical target, HD 125390 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 125390 b is a rare exoplanet

HD 125390 b scores 48 points on Spacedle's rarity scale, which places it in the rare tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Gas giant and Eccentric orbit — 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.