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Trash star 12 EP

HD 8440

RA 21.1327° · Dec 50.8033° · star

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Score breakdown

· 3 badges
12 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Never sets (northern circumpolar) +4
  • Star +3
Total score 12

3 more points to reach Common.

Badges

  • Star · +3
  • Never sets (northern circumpolar) · +4
  • White A-type star · +5

Trivia

Hard to believe

  • True brightness. It pours out about 3.6 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 8.4 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cassiopeia.
  • 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 October — 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 8490 K, against the Sun's 5778 K.

Properties

absmag
-11.56
bv
0.159
constellation
Cas
luminosity
3664375.7465
mag
8.44
name
HD 8440
spect
A0

Nearby objects

About HD 8440

HD 8440 is a trash star. It sits in the constellation Cas, shines at apparent magnitude 8.44 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 8440 in the constellation Cas. At apparent magnitude 8.44, it is an easy target for binoculars.

Like any astronomical target, HD 8440 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 8440 is a trash star

HD 8440 scores 12 points on Spacedle's rarity scale, which places it in the trash tier. Another 3 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, Never sets (northern circumpolar) 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.