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Common exoplanet 21 EP

HD 25171 b

RA 58.9575° · Dec -65.1863° · exoplanet

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Score breakdown

· 3 badges
21 pts · Common
Common 22 pts → Uncommon
  • Two suns in its sky +12
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 21

1 more point to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Two suns in its sky · +12

Trivia

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

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 7.8 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around November — 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. ≈ 3.2 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
0.595
diameter km
177311.18
discovery facility
La Silla Observatory
discovery method
Radial Velocity
discovery year
2010
dist ly
181.3904
eccentricity
0.042
eq temp k
190.04
host star teff
6125
insolation
0.2141
mag
7.77
mass earth
290.8145
multi star system
yes
name
HD 25171 b
orbital period days
1802.29
radius earth
13.9
semi major au
2.971
spect
F8 V
sys num planets
1
sys num stars
2

Nearby objects

About HD 25171 b

HD 25171 b is a common exoplanet. It lies about 181.4 light-years from Earth, shines at apparent magnitude 7.77, has spectral type F8 V and has an equilibrium temperature near 190 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 7.77, it is an easy target for binoculars.

Like any astronomical target, HD 25171 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 25171 b is a common exoplanet

HD 25171 b scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

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