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Epic exoplanet 75 EP

MASCARA-4 b

RA 147.5801° · Dec -66.1139° · exoplanet

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Score breakdown

· 7 badges
75 pts · Epic
Epic 78 pts → Anomaly
  • Ultra-hot Jupiter +26
  • Orbits a hot blue-white star +14
  • Two suns in its sky +12
  • Tidally locked +10
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
Total score 75

3 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Ultra-hot Jupiter · +26
  • Tidally locked · +10
  • Blasted by starlight · +4
  • Orbits a hot blue-white star · +14
  • Two suns in its sky · +12

Trivia

What makes it special

  • Ultra-hot Jupiter. So hot that iron vaporises on the dayside, blows around to the night side and rains back down as molten metal.

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 8.2 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around February — that's when to go looking.

Properties

density gcc
0.481
diameter km
216620.7594
discovery facility
Multiple Observatories
discovery method
Transit
discovery year
2020
dist ly
556.7352
eccentricity
0
eq temp k
2250
host star teff
7800
inclination
86.89
insolation
4913.69
mag
8.191
mass earth
532.3626
multi star system
yes
name
MASCARA-4 b
orbital period days
2.8241
radius earth
16.9816
semi major au
0.0474
spect
A7 V
sys num planets
1
sys num stars
2
tidally locked
yes
tidally locked inferred
yes

Nearby objects

About MASCARA-4 b

MASCARA-4 b is an epic exoplanet. It lies about 556.7 light-years from Earth, shines at apparent magnitude 8.19, has spectral type A7 V and has an equilibrium temperature near 2,250 K.

So hot that iron vaporises on the dayside, blows around to the night side and rains back down as molten metal.

How to see it

At apparent magnitude 8.19, it is an easy target for binoculars.

Like any astronomical target, MASCARA-4 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 MASCARA-4 b is an epic exoplanet

MASCARA-4 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 7 science badges — Confirmed exoplanet, Gas giant, Ultra-hot Jupiter, Tidally locked, Blasted by starlight, Orbits a hot blue-white 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.