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Rare exoplanet 41 EP

HAT-P-3 b

RA 206.0940° · Dec 48.0286° · exoplanet

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Score breakdown

· 5 badges
41 pts · Rare
Rare 50 pts → Epic
  • Two suns in its sky +12
  • Hot Jupiter +10
  • Tidally locked +10
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 41

9 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Tidally locked · +10
  • 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.

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 11.9 you'll want a small backyard telescope.
  • 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.

Could we get there?

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

Properties

density gcc
0.855
diameter km
134405.1911
discovery facility
HATNet
discovery method
Transit
discovery year
2007
dist ly
438.8559
eccentricity
0
eq temp k
1189
host star teff
5185
inclination
87.24
insolation
176.587
mag
11.856
mass earth
206.5895
multi star system
yes
name
HAT-P-3 b
orbital period days
2.8997
radius earth
10.5365
semi major au
0.0387
spect
K1
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About HAT-P-3 b

HAT-P-3 b is a rare exoplanet. It lies about 438.9 light-years from Earth, shines at apparent magnitude 11.86, has spectral type K1 and has an equilibrium temperature near 1,189 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 11.86, a small backyard telescope will bring it into view.

Like any astronomical target, HAT-P-3 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 HAT-P-3 b is a rare exoplanet

HAT-P-3 b scores 41 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Tidally locked 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.