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Rare star 39 EP

Arkab Posterior

RA 290.8046° · Dec -44.7998° · star

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Score breakdown

· 7 badges
39 pts · Rare
Rare 50 pts → Epic
  • Naked-eye visible +8
  • Has a proper name +8
  • Toward the galactic centre +8
  • Giant star +6
  • Star +3
  • On the zodiac +3
  • Yellow-white F-type star +3
Total score 39

11 more points to reach Epic.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Has a proper name · +8
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Yellow-white F-type star · +3
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads F2III — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

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 4.3 you can see it with your own eyes from a dark site, over in Sagittarius.
  • 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 July — 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. ≈ 2.4 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.199
bv
0.35
constellation
Sgr
dist ly
134.1652
luminosity
28.8669
mag
4.27
name
Arkab Posterior
named
yes
spect
F2III

About Arkab Posterior

Arkab Posterior is a rare star. It lies about 134.2 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 4.27 and has spectral type F2III.

Its spectrum reads F2III — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for Arkab Posterior in the constellation Sgr. At apparent magnitude 4.27, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Arkab Posterior 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 Arkab Posterior is a rare star

Arkab Posterior scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 7 science badges — Star, Naked-eye visible, Has a proper name, Toward the galactic centre, On the zodiac, Yellow-white F-type star and Giant 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.