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Common star 20 EP

HD 130021

RA 222.4044° · Dec -68.9362° · star

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Score breakdown

· 4 badges
20 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Giant star +6
  • Blue-white star +5
  • Star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Giant star · +6
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3III — 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.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

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 6.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Circinus.
  • 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 May — 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. ≈ 16.6 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-0.811
bv
-0.101
constellation
Cir
dist ly
945.3798
luminosity
183.8231
mag
6.5
name
HD 130021
spect
B3III

About HD 130021

HD 130021 is a common star. It lies about 945.4 light-years from Earth, sits in the constellation Cir, shines at apparent magnitude 6.5 and has spectral type B3III.

Its spectrum reads B3III — 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 130021 in the constellation Cir. At apparent magnitude 6.5, it is an easy target for binoculars.

Like any astronomical target, HD 130021 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 130021 is a common star

HD 130021 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, Hot blue B-type star, Giant star and Blue-white 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.