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Epic star 64 EP

9Alp Cam

RA 73.5125° · Dec 66.3427° · star

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Score breakdown

· 6 badges
64 pts · Epic
Epic 78 pts → Anomaly
  • Blazing O-type star +26
  • Supergiant +18
  • Naked-eye visible +8
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Star +3
Total score 64

14 more points to reach Anomaly.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • Blazing O-type star · +26
  • Supergiant · +18
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads O9.5Ia SB: — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.
  • Where it is in life. It is a luminous supergiant — among the largest and rarest stars in the galaxy.

Find it in the sky

  • How to spot it. At magnitude 4.3 you can see it with your own eyes from a dark site, over in Camelopardalis.
  • 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 December — 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) — 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 10230 K, against the Sun's 5778 K.

Properties

absmag
-15.74
bv
-0.008
constellation
Cam
luminosity
172186857.4986
mag
4.26
name
9Alp Cam
spect
O9.5Ia SB:

About 9Alp Cam

9Alp Cam is an epic star. It sits in the constellation Cam, shines at apparent magnitude 4.26 and has spectral type O9.5Ia SB:.

Its spectrum reads O9.5Ia SB: — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

How to see it

Look for 9Alp Cam in the constellation Cam. At apparent magnitude 4.26, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 9Alp Cam 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 9Alp Cam is an epic star

9Alp Cam scores 64 points on Spacedle's rarity scale, which places it in the epic tier. Another 14 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, Never sets (northern circumpolar), Blazing O-type star, Supergiant 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.