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Common star 21 EP

HD 109047

RA 188.0612° · Dec -62.4993° · star

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Score breakdown

· 4 badges
21 pts · Common
Common 22 pts → Uncommon
  • Under the Southern Cross +8
  • White A-type star +5
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Star · +3
  • Under the Southern Cross · +8
  • White A-type star · +5
  • Subgiant (leaving the main sequence) · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads A1IV — 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 subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 9.5 you'll want a small backyard telescope, over in Crux.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 13.9 million years at Voyager 1's speed (17 km/s).

Properties

absmag
2.55
bv
0.279
constellation
Cru
dist ly
789.7241
luminosity
8.3176
mag
9.47
name
HD 109047
spect
A1IV

About HD 109047

HD 109047 is a common star. It lies about 789.7 light-years from Earth, sits in the constellation Cru, shines at apparent magnitude 9.47 and has spectral type A1IV.

Its spectrum reads A1IV — 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 109047 in the constellation Cru. At apparent magnitude 9.47, a small backyard telescope will bring it into view.

Like any astronomical target, HD 109047 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 109047 is a common star

HD 109047 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 4 science badges — Star, Under the Southern Cross, White A-type star and Subgiant (leaving the main sequence) — 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.