← Back to dex
Uncommon star 30 EP

HD 217315

RA 344.8035° · Dec 52.3030° · star

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

Computing the sky for your location…

Score breakdown

· 5 badges
30 pts · Uncommon
Uncommon 34 pts → Rare
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
Total score 30

4 more points to reach Rare.

Badges

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

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9 — 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 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Andromeda.
  • 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 September — 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. ≈ 39.5 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 3.5 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
-2.213
bv
-0.035
constellation
And
dist ly
2249.3518
luminosity
668.6518
mag
6.98
name
HD 217315
spect
B9

About HD 217315

HD 217315 is an uncommon star. It lies about 2,249.4 light-years from Earth, sits in the constellation And, shines at apparent magnitude 6.98 and has spectral type B9.

Its spectrum reads B9 — 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 217315 in the constellation And. At apparent magnitude 6.98, it is an easy target for binoculars.

Like any astronomical target, HD 217315 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 217315 is an uncommon star

HD 217315 scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Distant (over 1,000 light-years), Hot blue B-type 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.