← Back to dex
Uncommon star 33 EP

HD 191781

RA 302.4608° · Dec 45.4029° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 4 badges
33 pts · Uncommon
Uncommon 34 pts → Rare
  • Supergiant +18
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Star +3
Total score 33

1 more point to reach Rare.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Supergiant · +18

Trivia

What it actually is

  • Spectral class. Its spectrum reads B0Ibp — 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 supergiant, hundreds of times wider than the Sun.

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 9.5 you'll want a small backyard telescope, 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.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 41.5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.209
bv
0.578
constellation
Cyg
dist ly
2363.4493
luminosity
71.8456
mag
9.51
name
HD 191781
spect
B0Ibp

About HD 191781

HD 191781 is an uncommon star. It lies about 2,363.4 light-years from Earth, sits in the constellation Cyg, shines at apparent magnitude 9.51 and has spectral type B0Ibp.

Its spectrum reads B0Ibp — 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 191781 in the constellation Cyg. At apparent magnitude 9.51, a small backyard telescope will bring it into view.

Like any astronomical target, HD 191781 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 191781 is an uncommon star

HD 191781 scores 33 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.

That score comes from 4 science badges — Star, Distant (over 1,000 light-years), Hot blue B-type star and Supergiant — 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.