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Common star 15 EP

HD 12493

RA 31.1568° · Dec 61.7445° · star

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Score breakdown

· 4 badges
15 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Never sets (northern circumpolar) +4
  • Star +3
  • Main-sequence star +2
Total score 15

7 more points to reach Uncommon.

Badges

  • Star · +3
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Main-sequence star · +2

Trivia

Hard to believe

  • True brightness. It pours out about 1.6 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

  • Spectral class. Its spectrum reads B8V — 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 9.3 you'll want a small backyard telescope, 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 October — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out yellow-white (B−V 0.4) — a shade brighter and crisper than our own Sun.
  • 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.

Properties

absmag
-10.67
bv
0.432
constellation
Cas
luminosity
1614358.5568
mag
9.33
name
HD 12493
spect
B8V

About HD 12493

HD 12493 is a common star. It sits in the constellation Cas, shines at apparent magnitude 9.33 and has spectral type B8V.

Its spectrum reads B8V — 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 HD 12493 in the constellation Cas. At apparent magnitude 9.33, a small backyard telescope will bring it into view.

Like any astronomical target, HD 12493 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 HD 12493 is a common star

HD 12493 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Never sets (northern circumpolar), Hot blue B-type star and Main-sequence 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.