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Trash star 8 EP

HD 218391

RA 347.0753° · Dec -51.7442° · 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 1.4 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 A1m... — 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 9.4 you'll want a small backyard telescope, over in Grus.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around September — 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 0.3) — 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 7600 K, against the Sun's 5778 K.

Properties

absmag
-10.55
bv
0.278
constellation
Gru
luminosity
1445439.7707
mag
9.45
name
HD 218391
spect
A1m...

About HD 218391

HD 218391 is a trash star. It sits in the constellation Gru, shines at apparent magnitude 9.45 and has spectral type A1m....

Its spectrum reads A1m... — 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 218391 in the constellation Gru. At apparent magnitude 9.45, a small backyard telescope will bring it into view.

Like any astronomical target, HD 218391 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 218391 is a trash star

HD 218391 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.