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Uncommon star 27 EP

HD 191091

RA 302.3539° · Dec -33.8743° · star

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Score breakdown

· 6 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Toward the galactic centre +8
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
  • On the zodiac +3
  • Main-sequence star +2
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B8/B9V — 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.

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 7.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Sagittarius.
  • Southern sky. It rides the southern half of the sky — an easier target the further south 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. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 12.2 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 1.1 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
0.635
bv
-0.032
constellation
Sgr
dist ly
692.4755
luminosity
48.5289
mag
7.27
name
HD 191091
spect
B8/B9V

About HD 191091

HD 191091 is an uncommon star. It lies about 692.5 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 7.27 and has spectral type B8/B9V.

Its spectrum reads B8/B9V — 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 191091 in the constellation Sgr. At apparent magnitude 7.27, it is an easy target for binoculars.

Like any astronomical target, HD 191091 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 191091 is an uncommon star

HD 191091 scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Toward the galactic centre, On the zodiac, 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.