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Epic exoplanet 75 EP

HD 20329 b

RA 49.1781° · Dec 15.6564° · exoplanet

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Score breakdown

· 8 badges
75 pts · Epic
Epic 78 pts → Anomaly
  • Denser than iron +18
  • Lava world +14
  • Ultra-short period +14
  • Super-Earth +8
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Blasted by starlight +4
  • Found by TESS +4
Total score 75

3 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Super-Earth · +8
  • Lava world · +14
  • Ultra-short period · +14
  • Denser than iron · +18
  • Blasted by starlight · +4
  • Found by TESS · +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

  • Denser than iron. It is packed tighter than solid iron — whatever it is made of, it is not ordinary rock.
  • A year in a day. Its entire year is over in 22.2 hours. Birthdays here would come round faster than meals.

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. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.

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 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.

Properties

density gcc
8.06
diameter km
21940.664
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit
discovery year
2022
dist ly
207.6948
eccentricity
0
eq temp k
2141
host star teff
5596
inclination
76.01
insolation
3474
mag
8.76
mass earth
7.42
name
HD 20329 b
orbital period days
0.9261
radius earth
1.72
semi major au
0.018
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About HD 20329 b

HD 20329 b is an epic exoplanet. It lies about 207.7 light-years from Earth, shines at apparent magnitude 8.76, has an equilibrium temperature near 2,141 K and spans roughly 1.72 Earth radii.

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

How to see it

At apparent magnitude 8.76, it is an easy target for binoculars.

Like any astronomical target, HD 20329 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 20329 b is an epic exoplanet

HD 20329 b scores 75 points on Spacedle's rarity scale, which places it in the epic tier. Another 3 points would lift it into a rarer tier.

That score comes from 8 science badges — Confirmed exoplanet, Super-Earth, Lava world, Ultra-short period, Denser than iron, Blasted by starlight, Found by TESS 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.