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Epic exoplanet 65 EP

HAT-P-1 b

RA 344.4454° · Dec 38.6749° · exoplanet

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Score breakdown

· 7 badges
65 pts · Epic
Epic 78 pts → Anomaly
  • Lava world +14
  • Puffy low-density world +12
  • Two suns in its sky +12
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 65

13 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • Puffy low-density world · +12
  • Orbits a Sun-like star · +8
  • Two suns in its sky · +12

Trivia

What makes it special

  • Lava world. Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

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 9.8 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 September — that's when to go looking.

Properties

density gcc
0.282
diameter km
188596.2202
discovery facility
HATNet
discovery method
Transit
discovery year
2006
dist ly
518.5195
eccentricity
0
eq temp k
1322
host star teff
5980
inclination
85.634
insolation
259.687
mag
9.827
mass earth
166.8607
multi star system
yes
name
HAT-P-1 b
orbital period days
4.4653
radius earth
14.7847
semi major au
0.0556
spect
G0 V
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

About HAT-P-1 b

HAT-P-1 b is an epic exoplanet. It lies about 518.5 light-years from Earth, shines at apparent magnitude 9.83, has spectral type G0 V and has an equilibrium temperature near 1,322 K.

Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

How to see it

At apparent magnitude 9.83, a small backyard telescope will bring it into view.

Like any astronomical target, HAT-P-1 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-1 b is an epic exoplanet

HAT-P-1 b scores 65 points on Spacedle's rarity scale, which places it in the epic tier. Another 13 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Gas giant, Lava world, Tidally locked, Puffy low-density world, Orbits a Sun-like star 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.