← Back to dex
Uncommon star 27 EP

12 Cas

RA 6.1979° · Dec 61.8311° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 5 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Giant star +6
  • Never sets (northern circumpolar) +4
  • Star +3
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9III — 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 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 5.4 you can see it with your own eyes from a dark site, over in Cassiopeia.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • 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.

Getting there

  • Aboard Voyager 1. ≈ 12.3 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.283
bv
0.008
constellation
Cas
dist ly
701.4109
luminosity
283.9226
mag
5.38
name
12 Cas
spect
B9III

About 12 Cas

12 Cas is an uncommon star. It lies about 701.4 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 5.38 and has spectral type B9III.

Its spectrum reads B9III — 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 12 Cas in the constellation Cas. At apparent magnitude 5.38, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 12 Cas 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 12 Cas is an uncommon star

12 Cas 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, Never sets (northern circumpolar), Hot blue B-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.