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Rare exoplanet 36 EP

HD 220773 b

RA 351.6145° · Dec 8.6429° · exoplanet

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Score breakdown

· 5 badges
36 pts · Rare
Rare 50 pts → Epic
  • Long-period world +10
  • Eccentric orbit +9
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 36

14 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Long-period world · +10
  • Eccentric orbit · +9
  • Orbits a Sun-like star · +8

Trivia

What it actually is

  • 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 7.1 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 2.9 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 257.2 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

density gcc
1.01
diameter km
173484.32
discovery facility
McDonald Observatory
discovery method
Radial Velocity
discovery year
2011
dist ly
164.7424
eccentricity
0.51
eq temp k
167.02
host star teff
5940
insolation
0.129
mag
7.1083
mass earth
460.8
name
HD 220773 b
orbital period days
3724.7
radius earth
13.6
semi major au
4.94
spect
F9
sys num planets
1
sys num stars
1

About HD 220773 b

HD 220773 b is a rare exoplanet. It lies about 164.7 light-years from Earth, shines at apparent magnitude 7.11, has spectral type F9 and has an equilibrium temperature near 167 K.

Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

How to see it

At apparent magnitude 7.11, it is an easy target for binoculars.

Like any astronomical target, HD 220773 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 220773 b is a rare exoplanet

HD 220773 b scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 14 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Long-period world, Eccentric orbit 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.