← Back to dex
Common variable star 20 EP

HD 184905

RA 293.6830° · Dec 43.9459° · star

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

Computing the sky for your location…

Score breakdown

· 5 badges
20 pts · Common
Common 22 pts → Uncommon
  • Variable star +5
  • White A-type star +5
  • Blue-white star +5
  • 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
  • White A-type star · +5
  • Blue-white star · +5
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A0p — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • 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 6.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cygnus.
  • 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 July — 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. ≈ 10.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.257
bv
-0.034
constellation
Cyg
dist ly
616.5519
luminosity
68.7385
mag
6.64
name
HD 184905
spect
A0p
var amplitude
0.05
var designation
V1264
var max
6.607
var min
6.657

About HD 184905

HD 184905 is a common variable star. It lies about 616.6 light-years from Earth, sits in the constellation Cyg, shines at apparent magnitude 6.64 and has spectral type A0p.

Its spectrum reads A0p — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 184905 in the constellation Cyg. At apparent magnitude 6.64, it is an easy target for binoculars.

Like any astronomical target, HD 184905 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 184905 is a common variable star

HD 184905 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, White A-type star, Blue-white 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.