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Common star 15 EP

HD 239689

RA 322.6914° · Dec 57.2000° · star

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Score breakdown

· 4 badges
15 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Never sets (northern circumpolar) +4
  • Star +3
  • Main-sequence star +2
Total score 15

7 more points to reach Uncommon.

Badges

  • Star · +3
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Main-sequence star · +2

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1.5V — 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 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cepheus.
  • 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 August — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 14.9 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.767
bv
0.182
constellation
Cep
dist ly
847.1586
luminosity
17.108
mag
8.84
name
HD 239689
spect
B1.5V

About HD 239689

HD 239689 is a common star. It lies about 847.2 light-years from Earth, sits in the constellation Cep, shines at apparent magnitude 8.84 and has spectral type B1.5V.

Its spectrum reads B1.5V — 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 239689 in the constellation Cep. At apparent magnitude 8.84, it is an easy target for binoculars.

Like any astronomical target, HD 239689 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 239689 is a common star

HD 239689 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Never sets (northern circumpolar), Hot blue B-type star and Main-sequence 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.