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Common exoplanet 15 EP

HD 5278 c

RA 12.5468° · Dec -83.7438° · exoplanet

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Score breakdown

· 3 badges
15 pts · Common
Common 22 pts → Uncommon
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Neptune-like +4
Total score 15

7 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Neptune-like · +4
  • Multi-planet system · +6

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 7.9 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 October — that's when to go looking.

Could we get there?

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

Properties

density gcc
1.12
diameter km
57275.338
discovery facility
Paranal Observatory
discovery method
Radial Velocity
discovery year
2021
dist ly
187.8156
eccentricity
0.07
eq temp k
664.95
host star teff
6203
insolation
32.6706
mag
7.94
mass earth
18.4
name
HD 5278 c
orbital period days
40.87
radius earth
4.49
semi major au
0.2416
spect
F V
sys num planets
2
sys num stars
1

About HD 5278 c

HD 5278 c is a common exoplanet. It lies about 187.8 light-years from Earth, shines at apparent magnitude 7.94, has spectral type F V and has an equilibrium temperature near 665 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 7.94, it is an easy target for binoculars.

Like any astronomical target, HD 5278 c 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 5278 c is a common exoplanet

HD 5278 c scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Neptune-like and Multi-planet system — 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.