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Trash star 8 EP

HD 202973

RA 319.5303° · Dec 40.4397° · star

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Score breakdown

· 2 badges
8 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Star +3
Total score 8

7 more points to reach Common.

Badges

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

Trivia

Hard to believe

  • True brightness. It pours out about 2.4 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 A0 — 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 8.9 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 August — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out brilliant white (B−V 0.2) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • 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 8370 K, against the Sun's 5778 K.

Properties

absmag
-11.1
bv
0.174
constellation
Cyg
luminosity
2398832.919
mag
8.9
name
HD 202973
spect
A0

Nearby objects

About HD 202973

HD 202973 is a trash star. It sits in the constellation Cyg, shines at apparent magnitude 8.9 and has spectral type A0.

Its spectrum reads A0 — 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 202973 in the constellation Cyg. At apparent magnitude 8.9, it is an easy target for binoculars.

Like any astronomical target, HD 202973 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 202973 is a trash star

HD 202973 scores 8 points on Spacedle's rarity scale, which places it in the trash tier. Another 7 points would lift it into a rarer tier.

That score comes from 2 science badges — Star and White A-type 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.