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Common star 20 EP

HD 123940

RA 213.0996° · Dec -57.8319° · star

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Score breakdown

· 4 badges
20 pts · Common
Common 22 pts → Uncommon
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B4/B5IV — 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.

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 9.4 you'll want a small backyard telescope, over in Centaurus.
  • 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 April — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 26.8 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 2.4 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
1.072
bv
0.51
constellation
Cen
dist ly
1524.0934
luminosity
32.4489
mag
9.42
name
HD 123940
spect
B4/B5IV

About HD 123940

HD 123940 is a common star. It lies about 1,524.1 light-years from Earth, sits in the constellation Cen, shines at apparent magnitude 9.42 and has spectral type B4/B5IV.

Its spectrum reads B4/B5IV — 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 123940 in the constellation Cen. At apparent magnitude 9.42, a small backyard telescope will bring it into view.

Like any astronomical target, HD 123940 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 123940 is a common star

HD 123940 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Distant (over 1,000 light-years), Hot blue B-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.