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Common star 19 EP

20 Oph

RA 252.4584° · Dec -10.7830° · star

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Score breakdown

· 4 badges
19 pts · Common
Common 22 pts → Uncommon
  • Naked-eye visible +8
  • Subgiant (leaving the main sequence) +5
  • Star +3
  • Yellow-white F-type star +3
Total score 19

3 more points to reach Uncommon.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Yellow-white F-type star · +3
  • Subgiant (leaving the main sequence) · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads F7IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

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 4.6 you can see it with your own eyes from a dark site, over in Ophiuchus.
  • 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 June — 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. ≈ 1.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
2.116
bv
0.478
constellation
Oph
dist ly
104.3031
luminosity
12.4051
mag
4.64
name
20 Oph
spect
F7IV

About 20 Oph

20 Oph is a common star. It lies about 104.3 light-years from Earth, sits in the constellation Oph, shines at apparent magnitude 4.64 and has spectral type F7IV.

Its spectrum reads F7IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for 20 Oph in the constellation Oph. At apparent magnitude 4.64, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 20 Oph 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 20 Oph is a common star

20 Oph scores 19 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Naked-eye visible, Yellow-white F-type star and Subgiant (leaving the main sequence) — 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.