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Uncommon exoplanet 33 EP

HD 109271 b

RA 188.3974° · Dec -11.6215° · exoplanet

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Score breakdown

· 5 badges
33 pts · Uncommon
Uncommon 34 pts → Rare
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Neptune-like +4
Total score 33

1 more point to reach Rare.

Badges

  • Confirmed exoplanet · +5
  • Neptune-like · +4
  • Tidally locked · +10
  • Multi-planet system · +6
  • Orbits a Sun-like star · +8

Trivia

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.
  • Crowded system. One of at least 2 planets orbiting its star.

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 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Could we get there?

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

Properties

density gcc
1.18
diameter km
54979.222
discovery facility
La Silla Observatory
discovery method
Radial Velocity
discovery year
2013
dist ly
182.2286
eccentricity
0.25
eq temp k
1128.86
host star teff
5783
insolation
320.4393
mag
8.04
mass earth
17.162
name
HD 109271 b
orbital period days
7.8543
radius earth
4.31
semi major au
0.079
spect
G5 V
sys num planets
2
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About HD 109271 b

HD 109271 b is an uncommon exoplanet. It lies about 182.2 light-years from Earth, shines at apparent magnitude 8.04, has spectral type G5 V and has an equilibrium temperature near 1,129 K.

It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.

How to see it

At apparent magnitude 8.04, it is an easy target for binoculars.

Like any astronomical target, HD 109271 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 109271 b is an uncommon exoplanet

HD 109271 b scores 33 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Neptune-like, Tidally locked, Multi-planet system 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.