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Uncommon star 29 EP

HD 128855

RA 220.1285° · Dec -40.6081° · star

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Score breakdown

· 5 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • White A-type star +5
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 29

5 more points to reach Rare.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • White A-type star · +5
  • Subgiant (leaving the main sequence) · +5
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads A1/A2IV — 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.

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 7.3 it is just past naked-eye reach — ordinary binoculars will pull it in, 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 May — 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. ≈ 46.6 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 4.1 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
-2.2
bv
0.082
constellation
Cen
dist ly
2651.6747
luminosity
660.6934
mag
7.35
name
HD 128855
spect
A1/A2IV

About HD 128855

HD 128855 is an uncommon star. It lies about 2,651.7 light-years from Earth, sits in the constellation Cen, shines at apparent magnitude 7.35 and has spectral type A1/A2IV.

Its spectrum reads A1/A2IV — 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 128855 in the constellation Cen. At apparent magnitude 7.35, it is an easy target for binoculars.

Like any astronomical target, HD 128855 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 128855 is an uncommon star

HD 128855 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Distant (over 1,000 light-years), White A-type star, Subgiant (leaving the main sequence) and Intrinsically luminous (Mv < −2) — 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.