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Trash star 9 EP

HD 202237

RA 318.3335° · Dec 40.4576° · star

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Score breakdown

· 2 badges
9 pts · Trash
Trash 15 pts → Common
  • Hot blue B-type star +6
  • Star +3
Total score 9

6 more points to reach Common.

Badges

  • Star · +3
  • Hot blue B-type star · +6

Trivia

Hard to believe

  • True brightness. It pours out about 2.3 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 B8 — 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.

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) — 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 10060 K, against the Sun's 5778 K.

Properties

absmag
-11.06
bv
0.005
constellation
Cyg
luminosity
2312064.7902
mag
8.94
name
HD 202237
spect
B8

Nearby objects

About HD 202237

HD 202237 is a trash star. It sits in the constellation Cyg, shines at apparent magnitude 8.94 and has spectral type B8.

Its spectrum reads B8 — 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 HD 202237 in the constellation Cyg. At apparent magnitude 8.94, it is an easy target for binoculars.

Like any astronomical target, HD 202237 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 202237 is a trash star

HD 202237 scores 9 points on Spacedle's rarity scale, which places it in the trash tier. Another 6 points would lift it into a rarer tier.

That score comes from 2 science badges — Star and Hot blue B-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.