← Back to dex
Rare star 36 EP

HR 5931

RA 238.9161° · Dec 18.6207° · star

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

Computing the sky for your location…

Score breakdown

· 6 badges
36 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Giant star +6
  • Blue-white star +5
  • Star +3
Total score 36

14 more points to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Giant star · +6
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads B8III — 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 giant. It has already exhausted its core hydrogen and swollen up enormously in response.

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 6.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Serpens.
  • 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 May — 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. ≈ 28.1 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-2.192
bv
-0.089
constellation
Ser
dist ly
1598.804
luminosity
655.8432
mag
6.26
name
HR 5931
spect
B8III

About HR 5931

HR 5931 is a rare star. It lies about 1,598.8 light-years from Earth, sits in the constellation Ser, shines at apparent magnitude 6.26 and has spectral type B8III.

Its spectrum reads B8III — 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 HR 5931 in the constellation Ser. At apparent magnitude 6.26, it is an easy target for binoculars.

Like any astronomical target, HR 5931 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 HR 5931 is a rare star

HR 5931 scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 14 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Distant (over 1,000 light-years), Hot blue B-type star, Giant star, Blue-white 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.