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Uncommon exoplanet 27 EP

HD 99492 b

RA 171.6897° · Dec 3.0071° · exoplanet

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Score breakdown

· 4 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Two suns in its sky +12
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Neptune-like +4
Total score 27

7 more points to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Neptune-like · +4
  • Multi-planet system · +6
  • 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

  • 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. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 7.6 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Properties

density gcc
0.87
diameter km
69393.728
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2004
dist ly
59.3728
eccentricity
0.034
eq temp k
622.27
host star teff
4929
insolation
23.2671
mag
7.5673
mass earth
25.5
multi star system
yes
name
HD 99492 b
orbital period days
17.0503
radius earth
5.44
semi major au
0.12
spect
K2 V
sys num planets
2
sys num stars
2

About HD 99492 b

HD 99492 b is an uncommon exoplanet. It lies about 59.4 light-years from Earth, shines at apparent magnitude 7.57, has spectral type K2 V and has an equilibrium temperature near 622 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 7.57, it is an easy target for binoculars.

Like any astronomical target, HD 99492 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 99492 b is an uncommon exoplanet

HD 99492 b scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Neptune-like, Multi-planet system 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.