Epic exoplanet 63 EP

HAT-P-39 b

RA 113.7583° · Dec 17.8300° · exoplanet

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Score breakdown

· 7 badges

63 pts · Epic

Epic 68 pts → Anomaly

Lava world +14
Puffy low-density world +12
Hot Jupiter +10
Distant (>1000 ly) +10
Blasted by starlight +8
Confirmed exoplanet +5
Gas giant +4

Total score 63

5 more points to reach Anomaly.

Badges

Confirmed exoplanet · +5
Gas giant · +4
Hot Jupiter · +10
Lava world · +14
Puffy low-density world · +12
Blasted by starlight · +8
Distant (>1000 ly) · +10

Trivia

What makes it special

Lava world. Its surface is likely an ocean of molten rock.
Cotton-candy planet. So low-density it would float on water.

Could we get there?

Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

Aboard Voyager 1. ≈ 39.9 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 3.5 million years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 22.7 thousand years in a starship at a tenth of light speed.
Distance. 2273 light-years from Earth.

Look-back time

Look-back time. Its light left before the last ice age ended.

Saying hello

Say hello. A radio message and its reply would take 4547 years round-trip.

Standing on it

A year here. A full year lasts just 3.5 Earth days.

By the numbers

Size. About 17.6× the width of Earth.
Volume. About 5460 Earths could fit inside it.
Mass. Roughly 190× Earth's mass — about 0.6 Jupiters.
Your weight. You'd weigh about 0.6× your Earth weight standing here.
Density. Less dense than water — drop it in a big enough ocean and it would float.
Temperature. Around 1479°C — hotter than a self-cleaning oven.

How we found it

Discovery. Found by HATNet using the transit method.

Properties

density gcc: 0.19
discovery facility: HATNet
discovery method: Transit
dist ly: 2273.3204
eccentricity: 0
eq temp k: 1752
insolation: 1915.6934
mass earth: 190.372
name: HAT-P-39 b
orbital period days: 3.5439
radius earth: 17.609
sys num planets: 1

About HAT-P-39 b

HAT-P-39 b is an epic exoplanet. It lies about 2,273.3 light-years from Earth, has an equilibrium temperature near 1,752 K, spans roughly 17.61 Earth radii and weighs about 190.37 Earth masses.

Its surface is likely an ocean of molten rock.

How to see it

Like any astronomical target, HAT-P-39 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-39 b is an epic exoplanet

HAT-P-39 b scores 63 points on Spacedle's rarity scale, which places it in the epic tier. Another 5 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Lava world, Puffy low-density world, Blasted by starlight and Distant (>1000 ly) — 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.