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Common variable star 20 EP

HD 154689

RA 255.8918° · Dec 57.4998° · star

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Score breakdown

· 5 badges
20 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Variable star +5
  • Never sets (northern circumpolar) +4
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

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.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

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 8.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Draco.
  • 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 June — 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. ≈ 15.9 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.972
bv
0.019
constellation
Dra
dist ly
905.989
luminosity
35.5795
mag
8.19
name
HD 154689
spect
B9
var amplitude
0.05
var designation
V360
var max
8.166
var min
8.216

About HD 154689

HD 154689 is a common variable star. It lies about 906 light-years from Earth, sits in the constellation Dra, shines at apparent magnitude 8.19 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 154689 in the constellation Dra. At apparent magnitude 8.19, it is an easy target for binoculars.

Like any astronomical target, HD 154689 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 154689 is a common variable star

HD 154689 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Never sets (northern circumpolar), Hot blue B-type star, Barely variable (under 0.05 mag) and A named variable 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.