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Common exoplanet 21 EP

HD 104985 b

RA 181.3158° · Dec 76.9053° · exoplanet

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Score breakdown

· 3 badges
21 pts · Common
Common 22 pts → Uncommon
  • Its star is visible to the naked eye +12
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 21

1 more point to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Its star is visible to the naked eye · +12

Trivia

What it actually is

  • What it is made of. Its density says rock, though lighter than Earth's mix: probably less iron, or a thick shell of water and ice over the top.

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 5.8 you can see it with your own eyes from a dark site.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • 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.

Getting there

  • Aboard Voyager 1. ≈ 5.8 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 512.2 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

density gcc
4.63
diameter km
163279.36
discovery facility
Okayama Astrophysical Observatory
discovery method
Radial Velocity
discovery year
2003
dist ly
328.0347
eccentricity
0.047
eq temp k
901.01
host star teff
4738
insolation
115.1548
mag
5.7939
mass earth
1766.8081
name
HD 104985 b
orbital period days
199.68
radius earth
12.8
semi major au
0.715
spect
G9 III
sys num planets
1
sys num stars
1

About HD 104985 b

HD 104985 b is a common exoplanet. It lies about 328 light-years from Earth, shines at apparent magnitude 5.79, has spectral type G9 III and has an equilibrium temperature near 901 K.

Its density says rock, though lighter than Earth's mix: probably less iron, or a thick shell of water and ice over the top.

How to see it

At apparent magnitude 5.79, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HD 104985 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 104985 b is a common exoplanet

HD 104985 b scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Gas giant and Its star is visible to the naked eye — 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.