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Rare star 38 EP

HD 165808

RA 272.1198° · Dec -16.4167° · star

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Score breakdown

· 7 badges
38 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Toward the galactic centre +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Star +3
  • On the zodiac +3
  • Main-sequence star +2
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
  • Main-sequence star · +2
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3V — 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.

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 7.7 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 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. ≈ 53.1 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-2.183
bv
0.192
constellation
Sgr
dist ly
3019.9629
luminosity
650.4292
mag
7.65
name
HD 165808
spect
B3V

About HD 165808

HD 165808 is a rare star. It lies about 3,020 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 7.65 and has spectral type B3V.

Its spectrum reads B3V — 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 165808 in the constellation Sgr. At apparent magnitude 7.65, it is an easy target for binoculars.

Like any astronomical target, HD 165808 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 165808 is a rare star

HD 165808 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 7 science badges — Star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Hot blue B-type star, Main-sequence star and Intrinsically luminous (Mv < −2) — 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.