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Uncommon star 27 EP

Kap Eri

RA 36.7463° · Dec -47.7038° · star

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Score breakdown

· 5 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B5IV — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • 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 4.2 you can see it with your own eyes from a dark site, over in Eridanus.
  • 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 October — 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. ≈ 8.9 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.722
bv
-0.136
constellation
Eri
dist ly
508.031
luminosity
425.4025
mag
4.24
name
Kap Eri
spect
B5IV

About Kap Eri

Kap Eri is an uncommon star. It lies about 508 light-years from Earth, sits in the constellation Eri, shines at apparent magnitude 4.24 and has spectral type B5IV.

Its spectrum reads B5IV — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

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

Like any astronomical target, Kap Eri 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 Kap Eri is an uncommon star

Kap Eri scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Naked-eye visible, Hot blue B-type star, Subgiant (leaving the main sequence) and Blue-white 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.