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Common star 17 EP

HD 227828

RA 301.9907° · Dec 35.7182° · star

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Score breakdown

· 3 badges
17 pts · Common
Common 22 pts → Uncommon
  • Deep red star +8
  • Hot blue B-type star +6
  • Star +3
Total score 17

5 more points to reach Uncommon.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Deep red star · +8

Trivia

Hard to believe

  • True brightness. It pours out about 1.6 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 B — 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 9.3 you'll want a small backyard telescope, 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 deep orange-red (B−V 1.5) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3850 K, against the Sun's 5778 K.

What's in a name

  • Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.

Properties

absmag
-10.7
bv
1.46
constellation
Cyg
luminosity
1659586.9074
mag
9.3
name
HD 227828
spect
B

About HD 227828

HD 227828 is a common star. It sits in the constellation Cyg, shines at apparent magnitude 9.3 and has spectral type B.

Its spectrum reads B — 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 227828 in the constellation Cyg. At apparent magnitude 9.3, a small backyard telescope will bring it into view.

Like any astronomical target, HD 227828 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 227828 is a common star

HD 227828 scores 17 points on Spacedle's rarity scale, which places it in the common tier. Another 5 points would lift it into a rarer tier.

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