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Common star 21 EP

HD 216438

RA 342.9927° · Dec 53.7098° · star

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Score breakdown

· 3 badges
21 pts · Common
Common 22 pts → Uncommon
  • Bright giant +12
  • Hot blue B-type star +6
  • Star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Bright giant · +12

Trivia

Hard to believe

  • True brightness. It pours out about 3.5 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 B1II — 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.
  • Where it is in life. It is a bright giant, well on its way to the largest stars there are.

Find it in the sky

  • How to spot it. At magnitude 8.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Lacerta.
  • 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 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) — 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.

Properties

absmag
-11.52
bv
0.022
constellation
Lac
luminosity
3531831.6979
mag
8.48
name
HD 216438
spect
B1II

Nearby objects

About HD 216438

HD 216438 is a common star. It sits in the constellation Lac, shines at apparent magnitude 8.48 and has spectral type B1II.

Its spectrum reads B1II — 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 216438 in the constellation Lac. At apparent magnitude 8.48, it is an easy target for binoculars.

Like any astronomical target, HD 216438 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 216438 is a common star

HD 216438 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 3 science badges — Star, Hot blue B-type star and Bright giant — 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.