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Rare star 47 EP

1 Cas

RA 346.6534° · Dec 59.4198° · star

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Score breakdown

· 8 badges
47 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Star +3
Total score 47

3 more points to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads B0.5IV — 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 4.8 you can see it with your own eyes from a dark site, over in Cassiopeia.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • 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. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 19.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-2.856
bv
-0.06
constellation
Cas
dist ly
1128.5676
luminosity
1208.9268
mag
4.84
name
1 Cas
spect
B0.5IV

About 1 Cas

1 Cas is a rare star. It lies about 1,128.6 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 4.84 and has spectral type B0.5IV.

Its spectrum reads B0.5IV — 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 1 Cas in the constellation Cas. At apparent magnitude 4.84, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 1 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 1 Cas is a rare star

1 Cas scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.

That score comes from 8 science badges — Star, Distant (over 1,000 light-years), Naked-eye visible, Never sets (northern circumpolar), Hot blue B-type star, Subgiant (leaving the main sequence), Blue-white star and Intrinsically luminous (Mv < −2) — 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.