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Rare exoplanet 45 EP

TrES-3 b

RA 268.0291° · Dec 37.5463° · exoplanet

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Score breakdown

· 6 badges
45 pts · Rare
Rare 50 pts → Epic
  • Lava world +14
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
Total score 45

5 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Tidally locked · +10
  • 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.

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 12.4 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 June — that's when to go looking.

Properties

density gcc
0.994
diameter km
191024.095
discovery facility
TrES
discovery method
Transit
discovery year
2007
dist ly
754.5195
eccentricity
0
eq temp k
1638
host star teff
5650
inclination
81.85
insolation
1025.5022
mag
12.362
mass earth
607.03
name
TrES-3 b
orbital period days
1.3062
radius earth
14.975
semi major au
0.0228
spect
G4 V
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About TrES-3 b

TrES-3 b is a rare exoplanet. It lies about 754.5 light-years from Earth, shines at apparent magnitude 12.36, has spectral type G4 V and has an equilibrium temperature near 1,638 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 12.36, it takes a larger telescope or a long-exposure image to capture.

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

TrES-3 b scores 45 points on Spacedle's rarity scale, which places it in the rare tier. Another 5 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Lava world, Tidally locked, 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.