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Uncommon star 29 EP

91Psi1Aqr

RA 348.9729° · Dec -9.0877° · star

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Score breakdown

· 6 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Binary star +6
  • Giant star +6
  • Star +3
  • On the zodiac +3
  • Orange K-type star +3
Total score 29

5 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Binary star · +6
  • On the zodiac · +3
  • Orange K-type star · +3
  • Giant star · +6

Trivia

What makes it special

  • Not one star but two. It is a binary: two stars orbiting a shared centre of mass. More than half of all the 'stars' you can see are actually multiple systems.

What it actually is

  • Spectral class. Its spectrum reads K0III — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.
  • 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 4.2 you can see it with your own eyes from a dark site, over in Aquarius.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

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

Properties

absmag
0.929
binary
yes
bv
1.107
constellation
Aqr
dist ly
149.8191
luminosity
37.0169
mag
4.24
name
91Psi1Aqr
spect
K0III

About 91Psi1Aqr

91Psi1Aqr is an uncommon star. It lies about 149.8 light-years from Earth, sits in the constellation Aqr, shines at apparent magnitude 4.24 and has spectral type K0III.

It is a binary: two stars orbiting a shared centre of mass. More than half of all the 'stars' you can see are actually multiple systems.

How to see it

Look for 91Psi1Aqr in the constellation Aqr. At apparent magnitude 4.24, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 91Psi1Aqr 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 91Psi1Aqr is an uncommon star

91Psi1Aqr scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, Binary star, On the zodiac, Orange K-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.