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Uncommon variable star 26 EP

34 Cyg

RA 304.4467° · Dec 38.0329° · star

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Score breakdown

· 5 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 26

8 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Hot blue B-type star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B2pe — 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.

Find it in the sky

  • How to spot it. At magnitude 4.8 you can see it with your own eyes from a dark site, 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.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out yellow-white (B−V 0.4) — a shade brighter and crisper than our own Sun.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 7010 K, against the Sun's 5778 K.

Properties

absmag
-15.23
bv
0.377
constellation
Cyg
luminosity
107646521.363
mag
4.77
name
34 Cyg
spect
B2pe
var amplitude
0.18
var designation
P
var max
4.688
var min
4.868

About 34 Cyg

34 Cyg is an uncommon variable star. It sits in the constellation Cyg, shines at apparent magnitude 4.77 and has spectral type B2pe.

Its spectrum reads B2pe — 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 34 Cyg in the constellation Cyg. At apparent magnitude 4.77, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 34 Cyg 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 34 Cyg is an uncommon variable star

34 Cyg scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Naked-eye visible, Hot blue B-type star, Gently variable 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.