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Epic exoplanet 51 EP

HAT-P-13 b

RA 129.8824° · Dec 47.3519° · exoplanet

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Score breakdown

· 7 badges
51 pts · Epic
Epic 78 pts → Anomaly
  • Lava world +14
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
Total score 51

27 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • Multi-planet system · +6
  • Blasted by starlight · +4
  • Orbits a Sun-like star · +8

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.
  • 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 10.4 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.

Properties

density gcc
0.3408
diameter km
181877.8996
discovery facility
HATNet
discovery method
Transit
discovery year
2009
dist ly
804.9856
eccentricity
0.0133
eq temp k
1740
host star teff
5653
inclination
83.4
insolation
1978.5245
mag
10.421
mass earth
270.462
name
HAT-P-13 b
orbital period days
2.9162
radius earth
14.258
semi major au
0.0438
spect
G4
sys num planets
2
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About HAT-P-13 b

HAT-P-13 b is an epic exoplanet. It lies about 805 light-years from Earth, shines at apparent magnitude 10.42, has spectral type G4 and has an equilibrium temperature near 1,740 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 10.42, a small backyard telescope will bring it into view.

Like any astronomical target, HAT-P-13 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-13 b is an epic exoplanet

HAT-P-13 b scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 27 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Gas giant, Lava world, Tidally locked, Multi-planet system, Blasted by starlight and Orbits a Sun-like star — 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.