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Rare variable star 44 EP

HD 228854

RA 304.6968° · Dec 36.3406° · star

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Score breakdown

· 4 badges
44 pts · Rare
Rare 50 pts → Epic
  • Blazing O-type star +26
  • Strongly variable +10
  • Variable star +5
  • A named variable star +3
Total score 44

6 more points to reach Epic.

Badges

  • Variable star · +5
  • Blazing O-type star · +26
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 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 O8 — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Find it in the sky

  • How to spot it. At magnitude 8.7 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 July — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.6) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
  • 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
-11.35
bv
0.591
constellation
Cyg
luminosity
3019951.7204
mag
8.65
name
HD 228854
spect
O8
var amplitude
0.75
var designation
V382
var max
8.429
var min
9.179

Nearby objects

About HD 228854

HD 228854 is a rare variable star. It sits in the constellation Cyg, shines at apparent magnitude 8.65 and has spectral type O8.

Its spectrum reads O8 — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

How to see it

Look for HD 228854 in the constellation Cyg. At apparent magnitude 8.65, it is an easy target for binoculars.

Like any astronomical target, HD 228854 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 228854 is a rare variable star

HD 228854 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Blazing O-type star, Strongly variable and A named variable 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.