← Back to dex
Rare star 38 EP

HD 166291

RA 272.6594° · Dec -19.1669° · star

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

Computing the sky for your location…

Score breakdown

· 6 badges
38 pts · Rare
Rare 50 pts → Epic
  • Bright giant +12
  • Toward the galactic centre +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Star +3
  • On the zodiac +3
Total score 38

12 more points to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Bright giant · +12

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3II — 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 bright giant, well on its way to the largest stars there are.

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 you'll want a small backyard telescope, 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 June — 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. ≈ 19.4 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.386
bv
0.2
constellation
Sgr
dist ly
1101.8783
luminosity
24.2996
mag
9.03
name
HD 166291
spect
B3II

About HD 166291

HD 166291 is a rare star. It lies about 1,101.9 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 9.03 and has spectral type B3II.

Its spectrum reads B3II — 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 166291 in the constellation Sgr. At apparent magnitude 9.03, a small backyard telescope will bring it into view.

Like any astronomical target, HD 166291 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 166291 is a rare star

HD 166291 scores 38 points on Spacedle's rarity scale, which places it in the rare tier. Another 12 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Hot blue B-type star and Bright giant — 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.