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Rare variable star 44 EP

HD 193793

RA 305.1166° · Dec 43.8545° · star

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Score breakdown

· 4 badges
44 pts · Rare
Rare 50 pts → Epic
  • Wolf-Rayet star (shedding itself) +34
  • Variable star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 44

6 more points to reach Epic.

Badges

  • Variable star · +5
  • Wolf-Rayet star (shedding itself) · +34
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads WC+... — a Wolf-Rayet star: a stellar monster shedding its own outer layers in a ferocious wind, on its way to a supernova.
  • 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 6.8 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.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out yellow-white (B−V 0.5) — 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 6570 K, against the Sun's 5778 K.

Properties

absmag
-13.22
bv
0.461
constellation
Cyg
luminosity
16904409.3164
mag
6.78
name
HD 193793
spect
WC+...
var amplitude
0.04
var designation
V1687
var max
6.761
var min
6.801

About HD 193793

HD 193793 is a rare variable star. It sits in the constellation Cyg, shines at apparent magnitude 6.78 and has spectral type WC+....

Its spectrum reads WC+... — a Wolf-Rayet star: a stellar monster shedding its own outer layers in a ferocious wind, on its way to a supernova.

How to see it

Look for HD 193793 in the constellation Cyg. At apparent magnitude 6.78, it is an easy target for binoculars.

Like any astronomical target, HD 193793 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 193793 is a rare variable star

HD 193793 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Wolf-Rayet star (shedding itself), 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.