← Back to dex
Common star 17 EP

HD 205384

RA 323.8049° · Dec -14.5987° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 4 badges
17 pts · Common
Common 22 pts → Uncommon
  • Giant star +6
  • White A-type star +5
  • Star +3
  • On the zodiac +3
Total score 17

5 more points to reach Uncommon.

Badges

  • Star · +3
  • On the zodiac · +3
  • White A-type star · +5
  • Giant star · +6

Trivia

Hard to believe

  • True brightness. It pours out about 1 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 A2III — 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.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

Find it in the sky

  • How to spot it. At magnitude 9.8 you'll want a small backyard telescope, over in Capricornus.
  • 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 August — 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.

Properties

absmag
-10.17
bv
0.22
constellation
Cap
luminosity
1018591.3881
mag
9.83
name
HD 205384
spect
A2III

About HD 205384

HD 205384 is a common star. It sits in the constellation Cap, shines at apparent magnitude 9.83 and has spectral type A2III.

Its spectrum reads A2III — 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 205384 in the constellation Cap. At apparent magnitude 9.83, a small backyard telescope will bring it into view.

Like any astronomical target, HD 205384 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 205384 is a common star

HD 205384 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 4 science badges — Star, On the zodiac, White A-type star and Giant 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.