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Rare star 34 EP

HD 192001

RA 302.7571° · Dec 42.1268° · star

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Score breakdown

· 3 badges
34 pts · Rare
Rare 50 pts → Epic
  • Blazing O-type star +26
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 34

16 more points to reach Epic.

Badges

  • Star · +3
  • Blazing O-type star · +26
  • Subgiant (leaving the main sequence) · +5

Trivia

Hard to believe

  • True brightness. It pours out about 4.2 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 O9.5IV — 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 subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

Find it in the sky

  • How to spot it. At magnitude 8.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cygnus.
  • 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 July — 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 0.3) — 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
-11.72
bv
0.307
constellation
Cyg
luminosity
4246195.6395
mag
8.28
name
HD 192001
spect
O9.5IV

About HD 192001

HD 192001 is a rare star. It sits in the constellation Cyg, shines at apparent magnitude 8.28 and has spectral type O9.5IV.

Its spectrum reads O9.5IV — 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 HD 192001 in the constellation Cyg. At apparent magnitude 8.28, it is an easy target for binoculars.

Like any astronomical target, HD 192001 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 192001 is a rare star

HD 192001 scores 34 points on Spacedle's rarity scale, which places it in the rare tier. Another 16 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, Blazing O-type star and Subgiant (leaving the main sequence) — 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.