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Trash star 13 EP

HD 183558

RA 291.9557° · Dec 48.1768° · star

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Score breakdown

· 3 badges
13 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Blue-white star +5
  • Star +3
Total score 13

2 more points to reach Common.

Badges

  • Star · +3
  • White A-type star · +5
  • Blue-white star · +5

Trivia

Hard to believe

  • True brightness. It pours out about 4.1 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

  • Spectral class. Its spectrum reads A5 — 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.

Find it in the sky

  • How to spot it. At magnitude 8.3 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 blue-white (B−V -0.2) — the hallmark of a surface far hotter than the Sun's.
  • 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 12550 K, against the Sun's 5778 K.

Properties

absmag
-11.69
bv
-0.153
constellation
Cyg
luminosity
4130475.0199
mag
8.31
name
HD 183558
spect
A5

Nearby objects

About HD 183558

HD 183558 is a trash star. It sits in the constellation Cyg, shines at apparent magnitude 8.31 and has spectral type A5.

Its spectrum reads A5 — 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 183558 in the constellation Cyg. At apparent magnitude 8.31, it is an easy target for binoculars.

Like any astronomical target, HD 183558 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 183558 is a trash star

HD 183558 scores 13 points on Spacedle's rarity scale, which places it in the trash tier. Another 2 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, White A-type star and Blue-white 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.