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Uncommon star 28 EP

8Sig Cas

RA 359.7522° · Dec 55.7549° · star

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Score breakdown

· 6 badges
28 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Star +3
  • Main-sequence star +2
Total score 28

6 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1V... — 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 on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.

Find it in the sky

  • How to spot it. At magnitude 4.9 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.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out blue-white (B−V -0.1) — the hallmark of a surface far hotter than the Sun's.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 11110 K, against the Sun's 5778 K.

Properties

absmag
-15.12
bv
-0.071
constellation
Cas
luminosity
97274722.3777
mag
4.88
name
8Sig Cas
spect
B1V...

About 8Sig Cas

8Sig Cas is an uncommon star. It sits in the constellation Cas, shines at apparent magnitude 4.88 and has spectral type B1V....

Its spectrum reads B1V... — 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 8Sig Cas in the constellation Cas. At apparent magnitude 4.88, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 8Sig 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 8Sig Cas is an uncommon star

8Sig Cas scores 28 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 6 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, Never sets (northern circumpolar), Hot blue B-type star, Main-sequence star 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.