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Common exoplanet 21 EP

17 Sco b

RA 243.4621° · Dec -11.8378° · 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 5.2 you can see it with your own eyes from a dark site.
  • 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 May — 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. ≈ 7.2 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 636.3 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

density gcc
3.51
diameter km
164554.98
discovery facility
Lick Observatory
discovery method
Radial Velocity
discovery year
2020
dist ly
407.5417
eccentricity
0.06
eq temp k
847.51
host star teff
4157
insolation
85.4316
mag
5.2261
mass earth
1373.0187
name
17 Sco b
orbital period days
578.38
radius earth
12.9
semi major au
1.45
spect
K3 III
sys num planets
1
sys num stars
1

About 17 Sco b

17 Sco b is a common exoplanet. It lies about 407.5 light-years from Earth, shines at apparent magnitude 5.23, has spectral type K3 III and has an equilibrium temperature near 848 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 5.23, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 17 Sco 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 17 Sco b is a common exoplanet

17 Sco 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.