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Common exoplanet 15 EP

HD 13908 b

RA 34.5609° · Dec 65.5942° · 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

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

  • 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. 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 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Properties

density gcc
0.562
diameter km
177311.18
discovery facility
Haute-Provence Observatory
discovery method
Radial Velocity
discovery year
2013
dist ly
259.462
eccentricity
0.02
eq temp k
993.25
host star teff
6255
insolation
168.6392
mag
7.52
mass earth
274.91
name
HD 13908 b
orbital period days
19.382
radius earth
13.9
semi major au
0.154
spect
F8 V
sys num planets
2
sys num stars
1

About HD 13908 b

HD 13908 b is a common exoplanet. It lies about 259.5 light-years from Earth, shines at apparent magnitude 7.52, has spectral type F8 V and has an equilibrium temperature near 993 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 7.52, it is an easy target for binoculars.

Like any astronomical target, HD 13908 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 13908 b is a common exoplanet

HD 13908 b 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.