← Back to dex
Rare star 39 EP

HD 217086

RA 344.1966° · Dec 62.7271° · star

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

Computing the sky for your location…

Score breakdown

· 4 badges
39 pts · Rare
Rare 50 pts → Epic
  • Blazing O-type star +26
  • Distant (over 1,000 light-years) +6
  • Never sets (northern circumpolar) +4
  • Star +3
Total score 39

11 more points to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Blazing O-type star · +26

Trivia

What it actually is

  • Spectral class. Its spectrum reads O7n — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

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 7.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cepheus.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • 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. ≈ 25 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 2.2 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
-0.561
bv
0.596
constellation
Cep
dist ly
1424.2619
luminosity
146.0158
mag
7.64
name
HD 217086
spect
O7n

About HD 217086

HD 217086 is a rare star. It lies about 1,424.3 light-years from Earth, sits in the constellation Cep, shines at apparent magnitude 7.64 and has spectral type O7n.

Its spectrum reads O7n — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

How to see it

Look for HD 217086 in the constellation Cep. At apparent magnitude 7.64, it is an easy target for binoculars.

Like any astronomical target, HD 217086 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 217086 is a rare star

HD 217086 scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Distant (over 1,000 light-years), Never sets (northern circumpolar) and Blazing O-type 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.